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Conserved domains on  [gi|1868432734|gb|QLG00072|]
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cytochrome c oxidase subunit I, partial (mitochondrion) [Actinopterygii sp. IOU6]

Protein Classification

heme-copper oxidase family protein( domain architecture ID 14)

heme-copper oxidase family protein may catalyze the transfer of electrons from an electron donor onto molecular oxygen

Graphical summary

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List of domain hits

 Name Accession Description Interval E-value
Heme_Cu_Oxidase_I super family cl00275
Heme-copper oxidase subunit I. Heme-copper oxidases are transmembrane protein complexes in ...
 1-199 3.67e-132

Heme-copper oxidase subunit I. Heme-copper oxidases are transmembrane protein complexes in the respiratory chains of prokaryotes and mitochondria which catalyze the reduction of O2 and simultaneously pump protons across the membrane. The superfamily is diverse in terms of electron donors, subunit composition, and heme types. The number of subunits varies from three to five in bacteria and up to 13 in mammalian mitochondria. It has been proposed that Archaea acquired heme-copper oxidases through gene transfer from Gram-positive bacteria. Membership in the superfamily is defined by subunit I, which contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme and a copper ion. It also contains a low-spin heme, believed to participate in the transfer of electrons to the binuclear center. Only subunit I is common to the entire superfamily. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from the electron donor on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I of cytochrome c oxidase (CcO) and ubiquinol oxidase. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electron transfer occurs in two segments: from the electron donor to the low-spin heme, and from the low-spin heme to the binuclear center. The first segment can be a multi-step process and varies among the different families, while the second segment, a direct transfer, is consistent throughout the superfamily.


The actual alignment was detected with superfamily member MTH00183:

Pssm-ID: 469701  Cd Length: 516  Bit Score: 380.42  E-value: 3.67e-132
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00183   35 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 114

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00183  115 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGVSSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 194

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00183  195 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 233
 
Name Accession Description Interval E-value
COX1 MTH00183
cytochrome c oxidase subunit I; Provisional
 1-199 3.67e-132

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177234  Cd Length: 516  Bit Score: 380.42  E-value: 3.67e-132
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00183   35 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 114

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00183  115 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGVSSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 194

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00183  195 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 233
Cyt_c_Oxidase_I cd01663
Cytochrome C oxidase subunit I. Cytochrome c oxidase (CcO), the terminal oxidase in the ...
 1-199 3.49e-117

Cytochrome C oxidase subunit I. Cytochrome c oxidase (CcO), the terminal oxidase in the respiratory chains of eukaryotes and most bacteria, is a multi-chain transmembrane protein located in the inner membrane of mitochondria and the cell membrane of prokaryotes. It catalyzes the reduction of O2 and simultaneously pumps protons across the membrane. The number of subunits varies from three to five in bacteria and up to 13 in mammalian mitochondria. Only subunits I and II are essential for function, but subunit III, which is also conserved, may play a role in assembly or oxygen delivery to the active site. Subunits I, II, and III of mammalian CcO are encoded within the mitochondrial genome and the remaining 10 subunits are encoded within the nuclear genome. Subunit I contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme (heme a3) and a copper ion (CuB). It also contains a low-spin heme (heme a), believed to participate in the transfer of electrons to the binuclear center. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from cytochrome c on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electrons are transferred from cytochrome c (the electron donor) to heme a via the CuA binuclear site in subunit II, and directly from heme a to the binuclear center.


Pssm-ID: 238833  Cd Length: 488  Bit Score: 341.38  E-value: 3.49e-117
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:cd01663    26 LLIRLELSQPGSQLGNDQLYNVIVTAHALIMIFFMVMPALIGGFGNWLVPLMIGAPDMAFPRLNNLSFWLLPPSLLLLLL 105

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:cd01663   106 SALVEGGAGTGWTVYPPLSSILAHSGPSVDLAIFSLHLAGISSILGAINFITTIFNMRAPGMTLEKMPLFVWSVLITAFL 185

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:cd01663   186 LLLSLPVLAGAITMLLTDRNFNTSFFDPAGGGDPILYQH 224
CyoB COG0843
Heme/copper-type cytochrome/quinol oxidase, subunit 1 [Energy production and conversion];
1-199 1.16e-64

Heme/copper-type cytochrome/quinol oxidase, subunit 1 [Energy production and conversion];


Pssm-ID: 440605  Cd Length: 535  Bit Score: 207.67  E-value: 1.16e-64
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPiMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:COG0843    38 LLMRLQLAGPGLGLLSPETYNQLFTMHGTIMIFFFATP-FLAGFGNYLVPLQIGARDMAFPRLNALSFWLYLFGGLLLLI 116

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:COG0843   117 SLFVGGAADVGWTFYPPLSGLEASPGVGVDLWLLGLALFGVGSILGGVNFIVTILKMRAPGMTLMRMPLFTWAALVTSIL 196

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:COG0843   197 ILLAFPVLAAALLLLLLDRSLGTHFFDPAGGGDPLLWQH 235
COX1 pfam00115
Cytochrome C and Quinol oxidase polypeptide I; Cytochrome c oxidase (E.C:7.1.1.9) is a key ...
 1-199 1.99e-40

Cytochrome C and Quinol oxidase polypeptide I; Cytochrome c oxidase (E.C:7.1.1.9) is a key enzyme in aerobic metabolism. Proton pumping haem-copper oxidases represent the terminal, energy-transfer enzymes of respiratory chains in prokaryotes and eukaryotes. The CuB-haem a3 (or haem o) binuclear centre, associated with the largest subunit I of cytochrome c and ubiquinol oxidases (E.C:1.10.3.11), is directly involved in the coupling between dioxygen reduction and proton pumping. Some terminal oxidases generate a transmembrane proton gradient across the plasma membrane (prokaryotes) or the mitochondrial inner membrane (eukaryotes). The enzyme complex consists of 3-4 subunits (prokaryotes) up to 13 polypeptides (mammals) of which only the catalytic subunit (equivalent to mammalian subunit I (COXI) is found in all haem-copper respiratory oxidases. The presence of a bimetallic centre (formed by a high-spin haem and copper B) as well as a low-spin haem, both ligated to six conserved histidine residues near the outer side of four transmembrane spans within CO I is common to all family members.


Pssm-ID: 459678  Cd Length: 432  Bit Score: 141.94  E-value: 1.99e-40
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPiMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:pfam00115  22 LLIRLQLAFPGLNFLSPLTYNQLRTLHGNLMIFWFATP-FLFGFGNYLVPLMIGARDMAFPRLNALSFWLVVLGAVLLLA 100

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGveaGAGTGWTVYPPLAGnlahagasVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQyQTPLFVWAVLITAVL 160
Cdd:pfam00115 101 SFG---GATTGWTEYPPLVG--------VDLWYIGLLLAGVSSLLGAINFIVTILKRRAPGMTL-RMPLFVWAILATAIL 168

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNttffdpAGGGDPILYQH 199
Cdd:pfam00115 169 ILLAFPVLAAALLLLLLDRSLG------AGGGDPLLDQH 201
QoxB TIGR02882
cytochrome aa3 quinol oxidase, subunit I; This family (QoxB) encodes subunit I of the aa3-type ...
 1-197 3.10e-35

cytochrome aa3 quinol oxidase, subunit I; This family (QoxB) encodes subunit I of the aa3-type quinone oxidase, one of several bacterial terminal oxidases. This complex couples oxidation of reduced quinones with the reduction of molecular oxygen to water and the pumping of protons to form a proton gradient utilized for ATP production. aa3-type oxidases contain two heme a cofactors as well as copper atoms in the active site. [Energy metabolism, Electron transport]


Pssm-ID: 131928  Cd Length: 643  Bit Score: 130.36  E-value: 3.10e-35
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGgFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:TIGR02882  73 LLMRAQLTVPDNKFLDAQHYNEIFTTHGVIMIIFMAMPFIIG-LMNIVVPLQIGARDVAFPVLNALSFWLFFAGAMLFNI 151

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:TIGR02882 152 SFVIGGSPDAGWTNYAPLAGPEFSPGVGVNYYLIALQISGIGTLMTGINFFVTILKMRAPGMKLMQMPMFTWTTLITTLI 231

                         170       180       190
                  ....*....|....*....|....*....|....*..
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILY 197
Cdd:TIGR02882 232 IIFAFPVLTVALALMTTDRIFDTAFFTVAHGGMPMLW 268
 
Name Accession Description Interval E-value
COX1 MTH00183
cytochrome c oxidase subunit I; Provisional
 1-199 3.67e-132

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177234  Cd Length: 516  Bit Score: 380.42  E-value: 3.67e-132
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00183   35 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 114

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00183  115 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGVSSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 194

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00183  195 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 233
COX1 MTH00103
cytochrome c oxidase subunit I; Validated
 1-199 1.64e-130

cytochrome c oxidase subunit I; Validated


Pssm-ID: 177165  Cd Length: 513  Bit Score: 376.14  E-value: 1.64e-130
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00103   35 LLIRAELGQPGTLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 114

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00103  115 SSMVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGVSSILGAINFITTIINMKPPAMSQYQTPLFVWSVLITAVL 194

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00103  195 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 233
COX1 MTH00153
cytochrome c oxidase subunit I; Provisional
 1-199 6.72e-125

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177210  Cd Length: 511  Bit Score: 361.88  E-value: 6.72e-125
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00153   33 LLIRAELGQPGSLIGDDQIYNVIVTAHAFIMIFFMVMPIMIGGFGNWLVPLMLGAPDMAFPRMNNMSFWLLPPSLTLLLS 112

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00153  113 SSMVESGAGTGWTVYPPLSSNIAHSGASVDLAIFSLHLAGISSILGAINFITTIINMRSKGMTLDRMPLFVWSVLITAIL 192

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00153  193 LLLSLPVLAGAITMLLTDRNLNTSFFDPAGGGDPILYQH 231
COX1 MTH00116
cytochrome c oxidase subunit I; Provisional
 1-199 4.67e-123

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177177  Cd Length: 515  Bit Score: 357.48  E-value: 4.67e-123
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00116   35 LLIRAELGQPGTLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 114

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00116  115 SSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTCINMKPPAMSQYQTPLFVWSVLITAVL 194

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00116  195 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 233
COX1 MTH00167
cytochrome c oxidase subunit I; Provisional
 1-199 4.08e-120

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177222  Cd Length: 512  Bit Score: 349.75  E-value: 4.08e-120
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00167   35 LLIRAELSQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMSFWLLPPSLLLLLA 114

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00167  115 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGSINFITTIINMKPPGITQYQTPLFVWSILVTTIL 194

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00167  195 LLLSLPVLAAAITMLLTDRNLNTTFFDPAGGGDPILYQH 233
Cyt_c_Oxidase_I cd01663
Cytochrome C oxidase subunit I. Cytochrome c oxidase (CcO), the terminal oxidase in the ...
 1-199 3.49e-117

Cytochrome C oxidase subunit I. Cytochrome c oxidase (CcO), the terminal oxidase in the respiratory chains of eukaryotes and most bacteria, is a multi-chain transmembrane protein located in the inner membrane of mitochondria and the cell membrane of prokaryotes. It catalyzes the reduction of O2 and simultaneously pumps protons across the membrane. The number of subunits varies from three to five in bacteria and up to 13 in mammalian mitochondria. Only subunits I and II are essential for function, but subunit III, which is also conserved, may play a role in assembly or oxygen delivery to the active site. Subunits I, II, and III of mammalian CcO are encoded within the mitochondrial genome and the remaining 10 subunits are encoded within the nuclear genome. Subunit I contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme (heme a3) and a copper ion (CuB). It also contains a low-spin heme (heme a), believed to participate in the transfer of electrons to the binuclear center. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from cytochrome c on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electrons are transferred from cytochrome c (the electron donor) to heme a via the CuA binuclear site in subunit II, and directly from heme a to the binuclear center.


Pssm-ID: 238833  Cd Length: 488  Bit Score: 341.38  E-value: 3.49e-117
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:cd01663    26 LLIRLELSQPGSQLGNDQLYNVIVTAHALIMIFFMVMPALIGGFGNWLVPLMIGAPDMAFPRLNNLSFWLLPPSLLLLLL 105

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:cd01663   106 SALVEGGAGTGWTVYPPLSSILAHSGPSVDLAIFSLHLAGISSILGAINFITTIFNMRAPGMTLEKMPLFVWSVLITAFL 185

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:cd01663   186 LLLSLPVLAGAITMLLTDRNFNTSFFDPAGGGDPILYQH 224
COX1 MTH00077
cytochrome c oxidase subunit I; Provisional
 1-199 3.85e-114

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 214419  Cd Length: 514  Bit Score: 334.60  E-value: 3.85e-114
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00077   35 LLIRAELSQPGTLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 114

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00077  115 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGVSSILGAINFITTSINMKPPSMSQYQTPLFVWSVLITAVL 194

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00077  195 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPVLYQH 233
COX1 MTH00142
cytochrome c oxidase subunit I; Provisional
 1-199 1.54e-109

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 214431  Cd Length: 511  Bit Score: 322.83  E-value: 1.54e-109
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00142   33 LLIRAELGQPGSLLGDDQLYNVIVTAHAFVMIFFMVMPVMIGGFGNWLVPLMLGAPDMAFPRMNNMSFWLLPPALLLLLS 112

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00142  113 SAAVESGAGTGWTVYPPLSSNLAHSGGSVDLAIFSLHLAGVSSILGAINFITTVINMRAGGMKFERVPLFVWSVKITAIL 192

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00142  193 LLLSLPVLAGAITMLLTDRNFNTSFFDPAGGGDPILYQH 231
COX1 MTH00223
cytochrome c oxidase subunit I; Provisional
 1-199 3.15e-109

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177260  Cd Length: 512  Bit Score: 321.93  E-value: 3.15e-109
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00223   32 LLIRAELGQPGALLGDDQLYNVIVTAHAFVMIFFLVMPMMIGGFGNWLVPLMLGAPDMAFPRLNNMSFWLLPPSLYLLLS 111

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00223  112 SSAVESGVGTGWTVYPPLSSNLAHAGPSVDLAIFSLHLAGVSSILGAINFITTIINMRSPGMQLERLPLFVWSVKVTAFL 191

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00223  192 LLLSLPVLAGAITMLLTDRNFNTSFFDPAGGGDPILYQH 230
COX1 MTH00037
cytochrome c oxidase subunit I; Provisional
 2-199 4.05e-98

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177112  Cd Length: 517  Bit Score: 293.66  E-value: 4.05e-98
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   2 LIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLAS 81
Cdd:MTH00037   36 IIRTELAQPGSLLQDDQIYNVIVTAHALVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLIPPSFLLLLAS 115

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  82 SGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVLL 161
Cdd:MTH00037  116 AGVESGAGTGWTIYPPLSSNIAHAGGSVDLAIFSLHLAGASSILASINFITTIINMRTPGMTFDRLPLFVWSVFITAFLL 195

                         170       180       190
                  ....*....|....*....|....*....|....*...
gi 1868432734 162 LLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00037  196 LLSLPVLAGAITMLLTDRNINTTFFDPAGGGDPILFQH 233
COX1 MTH00007
cytochrome c oxidase subunit I; Validated
 1-199 3.82e-96

cytochrome c oxidase subunit I; Validated


Pssm-ID: 133649  Cd Length: 511  Bit Score: 288.34  E-value: 3.82e-96
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00007   32 LLIRIELGQPGAFLGSDQLYNTIVTAHAFLMIFFLVMPVFIGGFGNWLVPLMLGAPDMAFPRLNNMSFWLLPPALILLVS 111

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00007  112 SAAVEKGVGTGWTVYPPLASNLAHAGPSVDLAIFSLHLAGVSSILGAINFITTVINMRWKGLRLERIPLFVWAVVITVVL 191

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00007  192 LLLSLPVLAGAITMLLTDRNLNTSFFDPAGGGDPILYQH 230
COX1 MTH00184
cytochrome c oxidase subunit I; Provisional
 1-199 9.33e-91

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177235  Cd Length: 519  Bit Score: 274.78  E-value: 9.33e-91
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00184   37 MLIRLELSAPGSMLGDDHLYNVIVTAHAFVMIFFLVMPVMIGGFGNWFVPLYIGAPDMAFPRLNNISFWLLPPALTLLLG 116

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00184  117 SAFVEQGAGTGWTVYPPLSSIQAHSGGSVDMAIFSLHLAGISSILGAMNFITTIFNMRAPGITMDRMPLFVWSILVTTFL 196

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00184  197 LLLSLPVLAGAITMLLTDRNFNTTFFDPAGGGDPILYQH 235
COX1 MTH00182
cytochrome c oxidase subunit I; Provisional
 1-199 1.09e-90

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 214451  Cd Length: 525  Bit Score: 274.78  E-value: 1.09e-90
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00182   37 MLIRLELSAPGAMLGDDHLYNVIVTAHAFIMIFFLVMPVMIGGFGNWLVPLYIGAPDMAFPRLNNISFWLLPPALILLLG 116

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00182  117 SAFVEQGAGTGWTVYPPLSSIQAHSGGAVDMAIFSLHLAGVSSILGAINFITTIFNMRAPGVTFNRLPLFVWSILITAFL 196

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00182  197 LLLSLPVLAGAITMLLTDRNFNTTFFDPAGGGDPILFQH 235
COX1 MTH00079
cytochrome c oxidase subunit I; Provisional
 1-199 2.42e-84

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177148  Cd Length: 508  Bit Score: 258.07  E-value: 2.42e-84
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00079   36 LIIRLELSKPGLLLGNGQLYNSVITAHAILMIFFMVMPSMIGGFGNWMLPLMLGAPDMSFPRLNNLSFWLLPTSLFLILD 115

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAgNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00079  116 SCFVDMGPGTSWTVYPPLS-TLGHPGSSVDLAIFSLHCAGISSILGGINFMVTTKNLRSSSISLEHMSLFVWTVFVTVFL 194

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00079  195 LVLSLPVLAGAITMLLTDRNLNTSFFDPSTGGNPLLYQH 233
COX1 MTH00026
cytochrome c oxidase subunit I; Provisional
 1-199 1.48e-82

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 164599  Cd Length: 534  Bit Score: 254.17  E-value: 1.48e-82
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00026   36 MLIRLELSSPGSMLGDDHLYNVIVTAHAFVMIFFLVMPTMIGGFGNWFVPLMIGAPDMAFPRLNNISFWLLPPALFLLLG 115

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:MTH00026  116 SSLVEQGAGTGWTVYPPLASIQAHSGGSVDMAIFSLHLAGLSSILGAMNFITTVMNMRTPGMTMSRIPLFVWSVFITAIL 195

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00026  196 LLLSLPVLAGAITMLLTDRNFNTTFFDPAGGGDPILYQH 234
Heme_Cu_Oxidase_I cd00919
Heme-copper oxidase subunit I. Heme-copper oxidases are transmembrane protein complexes in ...
 1-199 2.84e-73

Heme-copper oxidase subunit I. Heme-copper oxidases are transmembrane protein complexes in the respiratory chains of prokaryotes and mitochondria which catalyze the reduction of O2 and simultaneously pump protons across the membrane. The superfamily is diverse in terms of electron donors, subunit composition, and heme types. The number of subunits varies from three to five in bacteria and up to 13 in mammalian mitochondria. It has been proposed that Archaea acquired heme-copper oxidases through gene transfer from Gram-positive bacteria. Membership in the superfamily is defined by subunit I, which contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme and a copper ion. It also contains a low-spin heme, believed to participate in the transfer of electrons to the binuclear center. Only subunit I is common to the entire superfamily. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from the electron donor on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I of cytochrome c oxidase (CcO) and ubiquinol oxidase. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electron transfer occurs in two segments: from the electron donor to the low-spin heme, and from the low-spin heme to the binuclear center. The first segment can be a multi-step process and varies among the different families, while the second segment, a direct transfer, is consistent throughout the superfamily.


Pssm-ID: 238461  Cd Length: 463  Bit Score: 228.18  E-value: 2.84e-73
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPlMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:cd00919    24 LLIRLELATPGSLFLDPQLYNQLVTAHGVIMIFFFVMPAIFGGFGNLLPP-LIGARDLAFPRLNNLSFWLFPPGLLLLLS 102

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:cd00919   103 SVLVGGGAGTGWTFYPPLSTLSYSSGVGVDLAILGLHLAGVSSILGAINFITTILNMRAPGMTLDKMPLFVWSVLVTAIL 182

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:cd00919   183 LLLALPVLAAALVMLLLDRNFGTSFFDPAGGGDPVLYQH 221
CyoB COG0843
Heme/copper-type cytochrome/quinol oxidase, subunit 1 [Energy production and conversion];
1-199 1.16e-64

Heme/copper-type cytochrome/quinol oxidase, subunit 1 [Energy production and conversion];


Pssm-ID: 440605  Cd Length: 535  Bit Score: 207.67  E-value: 1.16e-64
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPiMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:COG0843    38 LLMRLQLAGPGLGLLSPETYNQLFTMHGTIMIFFFATP-FLAGFGNYLVPLQIGARDMAFPRLNALSFWLYLFGGLLLLI 116

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:COG0843   117 SLFVGGAADVGWTFYPPLSGLEASPGVGVDLWLLGLALFGVGSILGGVNFIVTILKMRAPGMTLMRMPLFTWAALVTSIL 196

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:COG0843   197 ILLAFPVLAAALLLLLLDRSLGTHFFDPAGGGDPLLWQH 235
COX1 MTH00048
cytochrome c oxidase subunit I; Provisional
 1-199 2.27e-56

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177123  Cd Length: 511  Bit Score: 185.65  E-value: 2.27e-56
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:MTH00048   36 LLIRLNFLDPYYNVISLDVYNFLITNHGIIMIFFFLMPVLIGGFGNYLLPLLLGLSDLNLPRLNALSAWLLVPSIVFLLL 115

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SsgVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISqYQTPLFVWAVLITAVL 160
Cdd:MTH00048  116 S--MCLGAGVGWTFYPPLSSSLFSSSWGVDFLMFSLHLAGVSSLFGSINFICTIYSAFMTNVF-SRTSIILWSYLFTSIL 192

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:MTH00048  193 LLLSLPVLAAAITMLLFDRNFGSAFFDPLGGGDPVLFQH 231
Ubiquinol_Oxidase_I cd01662
Ubiquinol oxidase subunit I. Ubiquinol oxidase, the terminal oxidase in the respiratory ...
 1-199 1.16e-55

Ubiquinol oxidase subunit I. Ubiquinol oxidase, the terminal oxidase in the respiratory chains of aerobic bacteria, is a multi-chain transmembrane protein located in the cell membrane. It catalyzes the reduction of O2 and simultaneously pumps protons across the membrane. The number of subunits in ubiquinol oxidase varies from two to five. Subunit I contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme and a copper ion. It also contains a low-spin heme, believed to participate in the transfer of electrons from ubiquinol to the binuclear center. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from ubiquinol on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I. It is generally believed that the channels contain water molecules that act as 'proton wires' to transfer the protons. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electrons are believed to be transferred directly from ubiquinol (the electron donor) to the low-spin heme, and directly from the low-spin heme to the binuclear center.


Pssm-ID: 238832  Cd Length: 501  Bit Score: 183.55  E-value: 1.16e-55
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGgFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:cd01662    30 LLMRTQLALPGNDFLSPEHYNQIFTMHGTIMIFLFAMPLVFG-LMNYLVPLQIGARDVAFPRLNALSFWLFLFGGLLLNA 108

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:cd01662   109 SLLIGGFPDAGWFAYPPLSGLEYSPGVGVDYWILGLQFSGIGTLLGAINFIVTILKMRAPGMTLMRMPIFTWTTLVTSIL 188

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQH 199
Cdd:cd01662   189 ILFAFPVLTAALALLELDRYFGTHFFTNALGGNPMLWQH 227
COX1 pfam00115
Cytochrome C and Quinol oxidase polypeptide I; Cytochrome c oxidase (E.C:7.1.1.9) is a key ...
 1-199 1.99e-40

Cytochrome C and Quinol oxidase polypeptide I; Cytochrome c oxidase (E.C:7.1.1.9) is a key enzyme in aerobic metabolism. Proton pumping haem-copper oxidases represent the terminal, energy-transfer enzymes of respiratory chains in prokaryotes and eukaryotes. The CuB-haem a3 (or haem o) binuclear centre, associated with the largest subunit I of cytochrome c and ubiquinol oxidases (E.C:1.10.3.11), is directly involved in the coupling between dioxygen reduction and proton pumping. Some terminal oxidases generate a transmembrane proton gradient across the plasma membrane (prokaryotes) or the mitochondrial inner membrane (eukaryotes). The enzyme complex consists of 3-4 subunits (prokaryotes) up to 13 polypeptides (mammals) of which only the catalytic subunit (equivalent to mammalian subunit I (COXI) is found in all haem-copper respiratory oxidases. The presence of a bimetallic centre (formed by a high-spin haem and copper B) as well as a low-spin haem, both ligated to six conserved histidine residues near the outer side of four transmembrane spans within CO I is common to all family members.


Pssm-ID: 459678  Cd Length: 432  Bit Score: 141.94  E-value: 1.99e-40
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPiMIGGFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:pfam00115  22 LLIRLQLAFPGLNFLSPLTYNQLRTLHGNLMIFWFATP-FLFGFGNYLVPLMIGARDMAFPRLNALSFWLVVLGAVLLLA 100

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGveaGAGTGWTVYPPLAGnlahagasVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQyQTPLFVWAVLITAVL 160
Cdd:pfam00115 101 SFG---GATTGWTEYPPLVG--------VDLWYIGLLLAGVSSLLGAINFIVTILKRRAPGMTL-RMPLFVWAILATAIL 168

                         170       180       190
                  ....*....|....*....|....*....|....*....
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNttffdpAGGGDPILYQH 199
Cdd:pfam00115 169 ILLAFPVLAAALLLLLLDRSLG------AGGGDPLLDQH 201
PRK15017 PRK15017
cytochrome o ubiquinol oxidase subunit I; Provisional
 20-197 5.26e-36

cytochrome o ubiquinol oxidase subunit I; Provisional


Pssm-ID: 184978  Cd Length: 663  Bit Score: 132.75  E-value: 5.26e-36
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  20 YNVIVTAHAFVMIFFMVMPIMIGgFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLASSGVEAGAGTGWTVYPPLA 99
Cdd:PRK15017   99 YDQIFTAHGVIMIFFVAMPFVIG-LMNLVVPLQIGARDVAFPFLNNLSFWFTVVGVILVNVSLGVGEFAQTGWLAYPPLS 177

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734 100 GNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVLLLLSLPVLAAGITMLLTDR 179
Cdd:PRK15017  178 GIEYSPGVGVDYWIWSLQLSGIGTTLTGINFFVTILKMRAPGMTMFKMPVFTWASLCANVLIIASFPILTVTVALLTLDR 257

                         170
                  ....*....|....*...
gi 1868432734 180 NLNTTFFDPAGGGDPILY 197
Cdd:PRK15017  258 YLGTHFFTNDMGGNMMMY 275
QoxB TIGR02882
cytochrome aa3 quinol oxidase, subunit I; This family (QoxB) encodes subunit I of the aa3-type ...
 1-197 3.10e-35

cytochrome aa3 quinol oxidase, subunit I; This family (QoxB) encodes subunit I of the aa3-type quinone oxidase, one of several bacterial terminal oxidases. This complex couples oxidation of reduced quinones with the reduction of molecular oxygen to water and the pumping of protons to form a proton gradient utilized for ATP production. aa3-type oxidases contain two heme a cofactors as well as copper atoms in the active site. [Energy metabolism, Electron transport]


Pssm-ID: 131928  Cd Length: 643  Bit Score: 130.36  E-value: 3.10e-35
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734   1 LLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGgFGNWLIPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLA 80
Cdd:TIGR02882  73 LLMRAQLTVPDNKFLDAQHYNEIFTTHGVIMIIFMAMPFIIG-LMNIVVPLQIGARDVAFPVLNALSFWLFFAGAMLFNI 151

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1868432734  81 SSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGISSILGAINFITTIINMKPPAISQYQTPLFVWAVLITAVL 160
Cdd:TIGR02882 152 SFVIGGSPDAGWTNYAPLAGPEFSPGVGVNYYLIALQISGIGTLMTGINFFVTILKMRAPGMKLMQMPMFTWTTLITTLI 231

                         170       180       190
                  ....*....|....*....|....*....|....*..
gi 1868432734 161 LLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILY 197
Cdd:TIGR02882 232 IIFAFPVLTVALALMTTDRIFDTAFFTVAHGGMPMLW 268
 
Blast search parameters
Data Source: Precalculated data, version = cdd.v.3.21
Preset Options:Database: CDSEARCH/cdd   Low complexity filter: no  Composition Based Adjustment: yes   E-value threshold: 0.01

References:

  • Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
  • Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
  • Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
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