BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 17 (BTBD17); BTBD17, also termed galectin-3-binding protein-like, is a BTB-domain-containing Kelch-like protein. Its function remains unclear. It may be involved in hepatocellular carcinoma development and progression.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1958659138 185 AGPAVGWYHYAVSTGDEALRESCLQFLAWNLSAVAGSAEWGAVSPELLAQLLQRSDLVLQDELELFHALEAWL 257
Cdd:cd18493     2 VNHAVSWLQYAKMCGHKELAEACLEFIAWNFEKVLKSPDWLNLDLDLLVSLLQSSDLVVEDEYTLFQAVEKWL 74

BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 17 (BTBD17); BTBD17, also termed galectin-3-binding protein-like, is a BTB-domain-containing Kelch-like protein. Its function remains unclear. It may be involved in hepatocellular carcinoma development and progression.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1958659138 185 AGPAVGWYHYAVSTGDEALRESCLQFLAWNLSAVAGSAEWGAVSPELLAQLLQRSDLVLQDELELFHALEAWL 257
Cdd:cd18493     2 VNHAVSWLQYAKMCGHKELAEACLEFIAWNFEKVLKSPDWLNLDLDLLVSLLQSSDLVVEDEYTLFQAVEKWL 74

BTB And C-terminal Kelch; The BACK domain is found juxtaposed to the BTB domain; they are separated by as little as two residues.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958659138  188 AVGWYHYAVSTGDEALRESCLQFLAWNLSAVAGSAEWGAVSPELLAQLLQRSDLVLQDELELFHALEAWLGRTRPP-PTV 266
Cdd:smart00875   1 CLGIRRFADAHGLEELAEKALRFILQNFSEVSSSEEFLELPLEQLLELLSSDDLNVSSEEEVFEAVLRWVKHDPEKrREH 80

                           90       100
                   ....*....|....*....|
gi 1958659138  267 AERALRAIRYPMIPPAQLFQ 286
Cdd:smart00875  81 LPELLEHVRLPLLSPDYLLE 100

BTB/POZ domain; The BTB (for BR-C, ttk and bab) or POZ (for Pox virus and Zinc finger) domain is present near the N-terminus of a fraction of zinc finger (pfam00096) proteins and in proteins that contain the pfam01344 motif such as Kelch and a family of pox virus proteins. The BTB/POZ domain mediates homomeric dimerization and in some instances heteromeric dimerization. The structure of the dimerized PLZF BTB/POZ domain has been solved and consists of a tightly intertwined homodimer. The central scaffolding of the protein is made up of a cluster of alpha-helices flanked by short beta-sheets at both the top and bottom of the molecule. POZ domains from several zinc finger proteins have been shown to mediate transcriptional repression and to interact with components of histone deacetylase co-repressor complexes including N-CoR and SMRT. The POZ or BTB domain is also known as BR-C/Ttk or ZiN.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958659138  82 SDVVLRVQAvgtdevRAFHTHRLLLGLHSELFRELLSNQ---SEVVLQEPGDC-AAVFDKFIRYLYCGELtVLLAQAIPL 157
Cdd:pfam00651  11 CDVTLVVGD------KEFRAHKAVLAACSPYFKALFSGQeseSSVSEITLDDVsPEDFEALLEFMYTGKL-ISEENVDDL 83

                          90       100
                  ....*....|....*....|....
gi 1958659138 158 HRLATKYRVASLQRGVADYMRAHL 181
Cdd:pfam00651  84 LAAADKLQIPSLVDKCEEFLIKSL 107

BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 17 (BTBD17); BTBD17, also termed galectin-3-binding protein-like, is a BTB-domain-containing Kelch-like protein. Its function remains unclear. It may be involved in hepatocellular carcinoma development and progression.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1958659138 185 AGPAVGWYHYAVSTGDEALRESCLQFLAWNLSAVAGSAEWGAVSPELLAQLLQRSDLVLQDELELFHALEAWL 257
Cdd:cd18493     2 VNHAVSWLQYAKMCGHKELAEACLEFIAWNFEKVLKSPDWLNLDLDLLVSLLQSSDLVVEDEYTLFQAVEKWL 74

BTB And C-terminal Kelch; This domain is found associated with pfam00651 and pfam01344. The BACK domain is found juxtaposed to the BTB domain; they are separated by as little as two residues. This family appears to be closely related to the BTB domain (Finn RD, personal observation).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958659138 188 AVGWYHYAVSTGDEALRESCLQFLAWNLSAVAGSAEWGAVSPELLAQLLQRSDLVLQDELELFHALEAWLGRTRPP-PTV 266
Cdd:pfam07707   1 CLGIYRFADAYGCTELAEAALRFILQNFLEVAKSEEFLELSLEQLLELLSSDDLNVPSEEEVFEAVIRWVKHDVERrKKH 80

                          90       100
                  ....*....|....*....|...
gi 1958659138 267 AERALRAIRYPMIPPAQLFQLQA 289
Cdd:pfam07707  81 LPELLSAVRLPLLSPQYLLNLVE 103

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing (ZBTB) proteins, Kelch-like (KLHL) proteins, and similar proteins; This family includes a variety of BTB/POZ domain-containing proteins, such as zinc finger and BTB domain-containing (ZBTB) proteins and Kelch-like (KLHL) proteins. They have diverse functions, such as transcriptional regulation, chromatin remodeling, protein degradation and cytoskeletal regulation. Many BTB/POZ proteins contain one or two additional domains, such as kelch repeats, zinc-finger domains, FYVE (Fab1, YOTB, Vac1, and EEA1) fingers, or ankyrin repeats. These special additional domains or interaction partners provide unique characteristics and functions to BTB/POZ proteins. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958659138  82 SDVVLRVqavgtdEVRAFHTHRLLLGLHSELFRELL------SNQSEVVLqePGDCAAVFDKFIRYLYCGELTVLLAQAI 155
Cdd:cd18186     2 CDVTLVV------GGREFPAHRAVLAARSPYFRAMFssgmkeSSSSEIEL--DDVSPEAFEALLDYIYTGELELSEENVE 73

                  ....*....
gi 1958659138 156 PLHRLATKY 164
Cdd:cd18186    74 ELLAAADKL 82

Broad-Complex, Tramtrack and Bric a brac; Domain in Broad-Complex, Tramtrack and Bric a brac. Also known as POZ (poxvirus and zinc finger) domain. Known to be a protein-protein interaction motif found at the N-termini of several C2H2-type transcription factors as well as Shaw-type potassium channels. Known structure reveals a tightly intertwined dimer formed via interactions between N-terminal strand and helix structures. However in a subset of BTB/POZ domains, these two secondary structures appear to be missing. Be aware SMART predicts BTB/POZ domains without the beta1- and alpha1-secondary structures.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958659138   83 DVVLRVqavgtdEVRAFHTHRLLLGLHSELFRELLSN------QSEVVLQEpgDCAAVFDKFIRYLYCGELTVLLAQAIP 156
Cdd:smart00225   1 DVTLVV------GGKKFHAHKAVLAAHSPYFKALFSSdfkesdKSEIYLDD--VSPEDFRALLNFLYTGKLDLPEENVEE 72

                           90       100
                   ....*....|....*....|....*
gi 1958659138  157 LHRLATKYRVASLQRGVADYMRAHL 181
Cdd:smart00225  73 LLELADYLQIPGLVELCEEFLLKLL 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Mac-2-binding protein (MAC2BP/M2BP); M2BP is also called galectin-3-binding protein, basement membrane autoantigen p105, lectin galactoside-binding soluble 3-binding protein (LGALS3BP), or tumor-associated antigen 90K. It promotes integrin-mediated cell adhesion and may stimulate host defense against viruses and tumor cells. It contains a scavenger receptor cysteine-rich domain, followed by BTB and BACK domains. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958659138  84 VVLRVQAVGTDEVRaFHTHRLLLGLHSELFRELLSNQSEVVLQEPGDCAAVFDKFIRYLYCGELTVLLAQAIPLHRLATK 163
Cdd:cd18304    22 ISVLTAGGEEEELT-FCAHRVILMLSPEANFLHKTGSSNITLDVDEECLPHVPDFLRYFYTRQIDITLTSVKCFHKLASI 100

                  ....*..
gi 1958659138 164 YRVASLQ 170
Cdd:cd18304   101 YGVRKLR 107

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in RCC1 and BTB domain-containing protein 2 (RCBTB2); RCBTB2 is also called chromosome condensation 1-like (CHC1-L), RCC1-like G exchanging factor, or regulator of chromosome condensation and BTB domain-containing protein 2. It is a chromosome condensation regulator-like guanine nucleotide exchange factor (GEF) protein for the Ras-related GTPase Ran. It contains an RCC1 repeat, a BTB domain, and a BACK domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1958659138 100 HTHRLLLGLHSELFRELLSNQSEVVLQEPGDCAAVFDKFIRYLYCGELTVLLAQAIPLHRLATKYRVASLQR 171
Cdd:cd18354    33 YVHKVLLKIRCEHFRSLLNENEEEIIEMSQFSYPVYRAFLEYLYTDSISLSPEDAIGLLDLATFYRENRLKK 104

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Ankyrin repeat and BTB/POZ domain-containing protein 2 (ABTB2) and similar proteins; This family includes ABTB2, BTBD11, plant ARM repeat protein interacting with ABF2 (ARIA), and similar proteins. ABTB2, also called bood POZ containing gene type 2 (BPOZ-2), is a scaffold protein that controls the degradation of many biological proteins ranging from embryonic development to tumor progression. It may be involved in the initiation of hepatocyte growth. ABTB2 functions as an adaptor protein for the E3 ubiquitin ligase scaffold protein Cullin-3. It directly binds to eukaryotic elongation factor 1A1 (eEF1A1) to promote eEF1A1 ubiquitylation and degradation, and prevent translation. The BTBD11 gene has been recently identified as an all-trans retinoic acid (atRA)-responsive gene that lies downstream of atRA and its receptors in the regulation of neurite outgrowth and cell adhesion in neural as well as non-neural tissues. ARIA is an armadillo (ARM) repeat and BTB domain-containing protein that acts as a positive regulator of ABA response via the modulation of the transcriptional activity of ABF2. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958659138  82 SDVVLRVqavgtdEVRAFHTHRLLLGLHSELFRELLS-----NQSEVVlqEPGDCA-AVFDKFIRYLYCG---ELTVLLA 152
Cdd:cd18297    13 SDVTFLV------EGRPFYAHKIVLVTASDRFKSMLSsgsteAQTPVI--EIPDIRyDIFQLMMQYLYTGgveSLDVAQD 84

                          90
                  ....*....|....*....
gi 1958659138 153 QAIPLHRLATKYRVASLQR 171
Cdd:cd18297    85 DALELLRAASFFQLDGLKR 103

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain superfamily; Proteins in this superfamily are characterized by the presence of a common protein-protein interaction motif of about 100 amino acids, known as the BTB/POZ domain. Members include transcription factors, oncogenic proteins, ion channel proteins, and potassium channel tetramerization domain (KCTD) proteins. They have been identified in poxviruses and many eukaryotes, and have diverse functions, such as transcriptional regulation, chromatin remodeling, protein degradation and cytoskeletal regulation. Many BTB/POZ proteins contain one or two additional domains, such as kelch repeats, zinc-finger domains, FYVE (Fab1, YOTB, Vac1, and EEA1) fingers, or ankyrin repeats, among others. These special additional domains or interaction partners provide unique characteristics and functions to BTB/POZ proteins. In ion channel proteins and KCTD proteins, the BTB/POZ domain is also called the tetramerization (T1) domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958659138  99 FHTHRLLLGLHSELFRELL------SNQSEVVLQEPGdcAAVFDKFIRYLYCGELTV 149
Cdd:cd01165    10 FHVNKELLAQSSEYFRALFrggfreSGQAEINLRDIS--PEDFRALLEFLYGGKRDL 64

BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 19 (BTBD19); BTBD19 is a BTB-domain-containing Kelch-like protein. Its function remains unclear.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1958659138 195 AVSTGDEALRESCLQFLAWNLSAVAGSAEWGAVSPELLAQLLQrSDLVLQDELELFHALEAW 256
Cdd:cd18494    12 AVTYGQDELKERCLAFIEEHTEEVFKTKGFHELSDEALSVILR-SDKLRIDELDILKAVREW 72

first BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Rho-related BTB domain-containing proteins (RhoBTB); RhoBTB proteins constitute a subfamily of atypical members within the Rho family of small guanosine triphosphatases (GTPases), which is characterized by containing a GTPase domain (in most cases, non-functional) followed by a proline-rich region, tandem BTB domains, and a conserved C-terminal region. In vertebrates, the RhoBTB subfamily consists of 3 isoforms: RhoBTB1, RhoBTB2, and RhoBTB3. Orthologs are present in several other eukaryotes, such as Drosophila and Dictyostelium, but have been lost in plants and fungi. This model corresponds to the first BTB domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1958659138  82 SDVVLRVQavgtdEVRAFHTHRLLLGLHSELFRELLSNQSEVVLQEPGDCAAvFDKFIRYLYCGELT 148
Cdd:cd18299    13 ADVVFILQ-----GGVRIFAHRIVLAAASSVFADLFLMMTVVTLDSDITPEA-FRRVLEFLYTGVLD 73

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Influenza virus NS1A-binding protein (NS1-BP); NS1-BP is also called NS1-binding protein, aryl hydrocarbon receptor-associated protein 3 (ARA3), or IVNS1ABP. It is a novel protein that interacts with the influenza A virus nonstructural NS1 protein, which is relocalized in the nuclei of infected cells. It plays a role in cell division and in the dynamic organization of the actin skeleton as a stabilizer of actin filaments by association with F-actin through its kelch repeats. It also interacts with alpha-enolase/MBP-1 and is involved in c-Myc gene transcriptional control. NS1-BP contains BTB and BACK domains at the N-terminal region and kelch repeats at the C-terminal region. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958659138  83 DVVLRVqavGTDEVRAfhtHRLLLGLHSELFRELLSNQSE-----VVLQEPGDCAAvFDKFIRYLYCGELTVLLAQAIPL 157
Cdd:cd18306    20 DVILQV---GGHEIPA---HRAVLACASPYLFELFSSDSDgesilTVKLDGLDPDA-VEVLVNYAYTSRLEVPADLVKSV 92

                          90       100
                  ....*....|....*....|....
gi 1958659138 158 HRLATKYRVASLQRGVADYMRAHL 181
Cdd:cd18306    93 YSAAKKLKMDRVKKACGDFLLEKL 116

BACK (BTB and C-terminal Kelch) domain found in intracisternal A particle-promoted polypeptide (IPP); IPP, also termed Kelch-like protein 27 (KLHL27), is an actin-binding protein that may play a role in organizing the actin cytoskeleton.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958659138 189 VGWYHYAVSTGDEALRESCLQFLAWNLSAVAGSAEWGAVSPELLAQLLQRSDLVLQDELELFHALEAWLGR---TRPPPT 265
Cdd:cd18466     7 IGIFQFSEQIACHDLLEFTENYIHVHFLEVQSGEEFLGLTKDQLVKILRSEELSIEDEYQVFTAAMEWILKdvgKRKKHV 86

                          90
                  ....*....|....*....
gi 1958659138 266 VaeRALRAIRYPMIPPAQL 284
Cdd:cd18466    87 V--EVLEPVRFPLLPPQRL 103

first BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in BTB/POZ domain-containing protein 7 (BTBD7); BTBD7 is a crucial regulator that is essential for region-specific epithelial cell dynamics and branching morphogenesis. It has been implicated in various cancers. BTBD7 contains two BTB domains. This model corresponds to the first domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1958659138  81 ASDVVLRVQavGTDevraFHTHRLLLGLHSELFRELLSN----QSEVV--LQEPGDCAAVFDKFIRYLYCGEL 147
Cdd:cd18283     2 CTDVDLVFQ--GTC----FPVHRAILSARCPFFRDLLSSspgyGAEIPvdLPTAGIDVPMFSALLRYLYTGEF 68