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.

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                 ....*....|....*....|....*....|....*....|....*..
gi 568980022   1 MYEGRLDLHNLPVEDVLAAASYLHMYDIVKVCKGRLRKKDPDLETRT 47
Cdd:cd18956   83 MYEGRLDLRSLPVEDVLAAASYLHMYDIVKVCKGRLREKDPALPRGA 129

Kinetoplastid RNA Editing Protein A (KREPA); The KREPA 1-6 (TbMP81, 63, 42, 24, 19, and 18, respectively) proteins are components of the RNA editing complex of parasitic protozoans such as Trypanosoma and Leishmania species. These parasites have a uniquely organized mitochondrial genome, the kinetoplast. Most kinetoplast-transcribed mRNAs are cryptic and encode multiple subunits for the electron transport chain following maturation through a uridine insertion/deletion process called RNA editing. KREPAs participate in the site-specific insertion and deletion of U nucleotides in the kinetoplastid mitochondria pre-messenger RNA. The editosome, a high molecular mass enzyme complex, carries out the reaction with the help of critical enzymes and structural proteins. Five related editosome proteins KREPA1 (TbMP81), KREPA2 (TbMP63), KREPA3 (TbMP42), KREPA4 (TbMP24), KREPA5 (TbMP19), and KREPA6 (TbMP18) play critical roles in the structure and auxiliary functions of the editing process without any predicted catalytic function. The KREPA1, KREPA2, and KREPA3 proteins contain C2H2 zinc finger motifs and KREPA4 and KREPA6, contain RNA-binding domains but all have a conserved C-terminal sequences that resemble an oligonucleotide-binding (OB)-fold domain. Thus, this group of five proteins is likely to be involved in protein-protein and/or protein-RNA interactions. RNA editing is crucial for the parasite's survival in both its bloodstream and procyclic form life cycle stages which allows the parasite to adapt to its environment and maintain its viability.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568980022  45 TRTLGTELPGQPPHPLPSWSPAF-CQAAPKAKHPSLGVKATHPLPTFGppswQVaeqssgaldlslkpsPRPEQVHPPCR 123
Cdd:cd23959  104 DESLGPFRAARVPNPFSASSSTQrETHKTAQVAPPKAEPQTAPVTPFG----QL---------------PMFGQHPPPAK 164

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568980022 124 LQTSLCSSVQQVAQPLVKAEQDSFSEQDSSSPQSADRSPPPvcASAAQGLAVDLEPLHIEGTGSQQLGLPAEPVLDSEEl 203
Cdd:cd23959  165 PLPAAAAAQQSSASPGEVASPFASGTVSASPFATATDTAPS--SGAPDGFPAEASAPSPFAAPASAASFPAAPVANGEA- 241

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|...
gi 568980022 204 GPSRHlcICPLCCKLFPSTHALQLHLSAHFR---ERDSVRARLSPEgSVPTCP 253
Cdd:cd23959  242 ATPTH--ACTICGKAFSTHEGLRMHSKAKHGvelEKAKTAKRKKRR-SVPDLP 291

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 42 (ZBTB42); ZBTB42 is a transcriptional repressor that specifically binds DNA and probably acts by recruiting chromatin remodeling multiprotein complexes. It is enriched in skeletal muscles, especially at the neuromuscular junction. A ZBTB42 mutation has been identified to define a novel lethal congenital contracture syndrome (LCCS6), a lethal autosomal recessive form of arthrogryposis multiplex congenita (AMC). ZBTB42 contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 568980022   1 MYEGRLDLHNLPVEDVLAAASYLHMYDIVKVCKGRLRKKDPDLETRT 47
Cdd:cd18956   83 MYEGRLDLRSLPVEDVLAAASYLHMYDIVKVCKGRLREKDPALPRGA 129

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
                   ....*....|....*....|....*....|....*....
gi 568980022     1 MYEGRLDLHNLPVEDVLAAASYLHMYDIVKVCKGRLRKK 39
Cdd:smart00225  58 LYTGKLDLPEENVEELLELADYLQIPGLVELCEEFLLKL 96

FOG: Zn-finger [General function prediction only];

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                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 568980022 252 CPLCSKTFSCTYTLKRHERTHSGEKPYTC--VQCGKSFQYSHNLSRHAVVHTREKPH 306
Cdd:COG5048   36 CPNCTDSFSRLEHLTRHIRSHTGEKPSQCsySGCDKSFSRPLELSRHLRTHHNNPSD 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 42 (ZBTB42); ZBTB42 is a transcriptional repressor that specifically binds DNA and probably acts by recruiting chromatin remodeling multiprotein complexes. It is enriched in skeletal muscles, especially at the neuromuscular junction. A ZBTB42 mutation has been identified to define a novel lethal congenital contracture syndrome (LCCS6), a lethal autosomal recessive form of arthrogryposis multiplex congenita (AMC). ZBTB42 contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

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                 ....*....|....*....|....*....|....*....|....*..
gi 568980022   1 MYEGRLDLHNLPVEDVLAAASYLHMYDIVKVCKGRLRKKDPDLETRT 47
Cdd:cd18956   83 MYEGRLDLRSLPVEDVLAAASYLHMYDIVKVCKGRLREKDPALPRGA 129

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 18.2 and similar proteins; This subfamily is composed of Xenopus laevis zinc finger and BTB domain-containing protein 18.2, encoded by the znf238.2.L gene, and similar proteins. Many proteins in this group are annotated as zinc finger and BTB domain-containing protein 42 (ZBTB42). However, characterized mammalian ZBTB42 does not belong to this subfamily. ZBTB18.2, like ZBTB18, functions as a transcriptional repressor that plays a role in various developmental processes. Members of this family contain a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

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                 ....*....|....*....|....*....|....*....|
gi 568980022   1 MYEGRLDLHNLPVEDVLAAASYLHMYDIVKVCKGRLRKKD 40
Cdd:cd18325   82 MYEGKLEFSSLPVEDVLAAASYLHMYDIVKVCKGKLKDKE 121

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 3 (ZBTB3); ZBTB3 is a transcription factor essential for cancer cell growth via the regulation of the reactive oxygen species (ROS) detoxification pathway. ZBTB3 contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 568980022   1 MYEGRLDLHNLPVEDVLAAASYLHMYDIVKVCKGRLRKKDP 41
Cdd:cd18323   82 MYEGRLSFNDTPVEDVLAAASYLHMNDIVKVCKKRLQARAL 122

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 8B (ZBTB8B); ZBTB8B may be involved in transcriptional regulation. It contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                         10        20        30
                 ....*....|....*....|....*....|....
gi 568980022   1 MYEGRLDLHNLPVEDVLAAASYLHMYDIVKVCKG 34
Cdd:cd18330   78 LYSGKLDLCSENVIEVMSAASYLQMTDVVNFCKG 111

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 8A (ZBTB8A); ZBTB8A, also called BTB/POZ and zinc-finger domain-containing factor or BTB/POZ and zinc-finger domains factor on chromosome 1 (BOZ-F1), is a novel proto-oncoprotein that stimulates cell proliferation. It binds to all the proximal GC boxes to repress transcription, and it inhibits p53 acetylation without affecting p53 stability. It may be involved in gastric adenocarcinoma cell differentiation, cancer invasion, and metastasis. ZBTB8A contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                         10        20        30
                 ....*....|....*....|....*....|...
gi 568980022   1 MYEGRLDLHNLPVEDVLAAASYLHMYDIVKVCK 33
Cdd:cd18329   81 VYSGKLSLTSQNVIEVMSAASYLQMTDVISVCK 113

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like proteins KLHL1, KLHL4 and KLHL5; This family contains the Kelch-like proteins: KLHL1, KLHL4 and KLHL5, all of which share high identity and similarity with the Drosophila kelch protein, a component of ring canals. KLHL1 is a neuronal actin-binding protein that modulates voltage-gated CaV2.1 (P/Q-type) and CaV3.2 (alpha1H T-type) calcium channels. Family members contain a BTB domain and kelch repeat domains, characteristics of a kelch family protein. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                         10        20        30
                 ....*....|....*....|....*....|....*....
gi 568980022   1 MYEGRLDLHNLPVEDVLAAASYLHMYDIVKVCKGRLRKK 39
Cdd:cd18234   60 CYTGRLELKEDNVESLLATACLLQLSEVVEACCGFLMKQ 98

Kinetoplastid RNA Editing Protein A2 (KREPA2); The KREPA2 (TbMP63) protein is a component of the parasitic protozoan's KREPA RNA editing catalytic complex (RECC). Kinetoplastid RNA editing (KRE) proteins occur as pairs or sets of related proteins in multiple complexes. KREPA complex is composed of six components (KREPA1-6), which share a conserved C-terminal region containing an oligonucleotide-binding (OB)-fold-like domain. KREPAs are responsible for the site-specific insertion and deletion of U nucleotides in the kinetoplastid mitochondria pre-messenger RNA. Apart from the conserved C-terminal OB-fold domain, KREPA1, KREPA2, and KREPA3 contain two conserved C2H2 zinc-finger domains. KREPA2 and kinetoplastid RNA editing ligase 1 (KREL1) are specific for ligation post-U-deletion and are paralogous to KREL2 and KREPA1 that are specific for ligation post-U-insertion. KREPA2, is critical for RECC stability and KREL1 integration into the complex.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568980022  45 TRTLGTELPGQPPHPLPSWSPAF-CQAAPKAKHPSLGVKATHPLPTFGppswQVaeqssgaldlslkpsPRPEQVHPPCR 123
Cdd:cd23959  104 DESLGPFRAARVPNPFSASSSTQrETHKTAQVAPPKAEPQTAPVTPFG----QL---------------PMFGQHPPPAK 164

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568980022 124 LQTSLCSSVQQVAQPLVKAEQDSFSEQDSSSPQSADRSPPPvcASAAQGLAVDLEPLHIEGTGSQQLGLPAEPVLDSEEl 203
Cdd:cd23959  165 PLPAAAAAQQSSASPGEVASPFASGTVSASPFATATDTAPS--SGAPDGFPAEASAPSPFAAPASAASFPAAPVANGEA- 241

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|...
gi 568980022 204 GPSRHlcICPLCCKLFPSTHALQLHLSAHFR---ERDSVRARLSPEgSVPTCP 253
Cdd:cd23959  242 ATPTH--ACTICGKAFSTHEGLRMHSKAKHGvelEKAKTAKRKKRR-SVPDLP 291

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 46 (ZBTB46); ZBTB46 is also called BTB-ZF protein expressed in effector lymphocytes (BZEL), BTB/POZ domain-containing protein 4 (BTBD4), or zinc finger protein 340 (ZNF340). It is a conventional dendritic cell (cDC) lineage specific transcription factor that acts as a negative regulator required to prevent activation of classical dendritic cells in the steady state. It contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

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                 ....*....|....*....|....*....|....*..
gi 568980022   1 MYEGRLDLHNLPVEDVLAAASYLHMYDIVKVCKGRLR 37
Cdd:cd18230   81 MYSAHLALTSKNVIEVMSAASYLQMTDIVQACHNFIK 117