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        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24641603    49 DVILEVGpapsNVRFVAHSLVLGMHSGYLRSAIRLDETAAGTAAsvsasasisitgataascnpsssssaasssssavtt 128
Cdd:pfam00651  12 DVTLVVG----DKEFRAHKAVLAACSPYFKALFSGQESESSVSE------------------------------------ 51

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 24641603   129 asgellLYLSNVTADQFAPLLTYMYTGYLdLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:pfam00651  52 ------ITLDDVSPEDFEALLEFMYTGKL-ISEENVDDLLAAADKLQIPSLVDKCEEFL 103

zinc finger;

                           10        20
                   ....*....|....*....|...
gi 24641603    573 YVCVYCKHTFKSQYCYQKHAKRH 595
Cdd:smart00355   1 YRCPECGKVFKSKSALREHMRTH 23

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 24641603    49 DVILEVGpapsNVRFVAHSLVLGMHSGYLRSAIRLDETAAGTAAsvsasasisitgataascnpsssssaasssssavtt 128
Cdd:pfam00651  12 DVTLVVG----DKEFRAHKAVLAACSPYFKALFSGQESESSVSE------------------------------------ 51

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 24641603   129 asgellLYLSNVTADQFAPLLTYMYTGYLdLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:pfam00651  52 ------ITLDDVSPEDFEALLEFMYTGKL-ISEENVDDLLAAADKLQIPSLVDKCEEFL 103

DNA polymerase III subunits gamma and tau; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24641603  192 TEGYLNGNPAAQLCPVPSIPAKiirPIPSKATMPNFGFLPLPQAPPSVAPSAQPTAHQPTTGIAPVASASILSSFGTNTQ 271
Cdd:PRK14959 402 TQGPQGTAPAAGMTPSSAAPAT---PAPSAAPSPRVPWDDAPPAPPRSGIPPRPAPRMPEASPVPGAPDSVASASDAPPT 478

                 .
gi 24641603  272 H 272
Cdd:PRK14959 479 L 479

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 24641603    49 DVILEVGpapsNVRFVAHSLVLGMHSGYLRSAIRLDETAAGTAAsvsasasisitgataascnpsssssaasssssavtt 128
Cdd:pfam00651  12 DVTLVVG----DKEFRAHKAVLAACSPYFKALFSGQESESSVSE------------------------------------ 51

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 24641603   129 asgellLYLSNVTADQFAPLLTYMYTGYLdLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:pfam00651  52 ------ITLDDVSPEDFEALLEFMYTGKL-ISEENVDDLLAAADKLQIPSLVDKCEEFL 103

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 44 (ZBTB44); ZBTB44, also called BTB/POZ domain-containing protein 15 (BTBD15) or zinc finger protein 851 (ZNF851), may be involved in transcriptional regulation. Single-nucleotide polymorphisms of ZBTB44 showed a suggestive association with disease progression of Crohn's disease. ZBTB44 has also preferentially been recognized by sera of patients with peripheral T-cell lymphoma (PTCL). It contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 24641603 131 GELLLYLSNVTADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:cd18228  64 GKCVLDLHHVTVTGFAPLLEYAYTSTLSINTENIIDVLAAASYMQMFNVANTCSEFM 120

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in telomere zinc finger-associated protein (TZAP); TZAP is also called Krueppel-related zinc finger protein 3 (KR3), zinc finger and BTB domain-containing protein 48 (ZBTB48), or zinc finger protein 855 (ZNF855). It is a vertebrate telomere-binding protein involved in telomere length control. It directly binds the telomeric double-stranded 5'-TTAGGG-3' repeat. TZAP also acts as a transcription regulator that binds to promoter regions. It is a transcriptional activator of alternate reading frame (ARF) gene. It contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*
gi 24641603 142 ADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSF 186
Cdd:cd18232  63 AEVFGLLLDFFYTGELALTRENRDRVLLAAKELRVPEAVELCQRF 107

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 49 (ZBTB49); ZBTB49, also called zinc finger protein 509 (ZNF509), is a transcription factor that inhibits cell proliferation by activating either CDKN1A/p21 transcription or RB1 transcription. There are four ZNF509 isoforms generated by alternative splicing. Short ZNF509 (ZNF509S1, -S2 and -S3) isoforms contain one or two out of the seven zinc-fingers contained in long ZNF509 (ZNF509L). ZBTB49 contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|
gi 24641603 148 LLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:cd18233  72 ILDFMYTSHLDLNQDNVQVMLDIAQCLQVQNVLNMCYTFL 111

second BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Ankyrin repeat and BTB/POZ domain-containing protein 1 (ABTB1); ABTB1, also called elongation factor 1A-binding protein or bood POZ containing gene type 1 (BPOZ-1), is an anti-proliferative factor that may act as a mediator of the phosphatase and tensin homolog (PTEN) growth-suppressive signaling pathway. It may play a role in developmental processes. ABTB1 contains an ankyrin repeat and two BTB domains. This model corresponds to the second BTB domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 24641603 135 LYLSNVTADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSFLA 188
Cdd:cd18296  64 VTLHDVSPEVFAIVLYYIYTDDTDLPPENAYDVLYVADMYLLPGLKRLCGTVLA 117

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        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 24641603 137 LSNVTADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:cd18330  63 LDIVTSEAFSIILDFLYSGKLDLCSENVIEVMSAASYLQMTDVVNFCKGYI 113

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in myoneurin; Myoneurin, also called zinc finger and BTB domain-containing protein 31 (ZBTB31), is a novel member of the BTB/POZ-zinc finger family highly expressed in the neuromuscular system and is associated with neuromuscular junctions during the late embryonic period. It may function as a synaptic gene regulator. Myoneurin contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 24641603 138 SNVTADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICR 184
Cdd:cd18217  61 SQVSADGFQKLLEFIYTGNLNLDSWNVAEIHQAASYLGMEEVVAKCK 107

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in gigaxonin; Gigaxonin, also called Kelch-like protein 16 (KLHL16), may be a cytoskeletal component that directly or indirectly plays an important role in neurofilament architecture. It may also act as a substrate-specific adaptor of an E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins, including tubulin folding cofactor B (TBCB), microtubule-associated protein MAP1B, and glial fibrillary acidic protein (GFAP). Gigaxonin is mutated in giant axonal neuropathy. It contains a BTB domain and kelch repeats, 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        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 24641603 137 LSNVTADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:cd18245  60 LEGISVEVMEEILDYIYTGQIKLSEDNIQDIVQAADLLLMTDLKDLCCEFL 110

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in B-cell lymphoma 6 protein (BCL-6); BCL-6 is also called B-cell lymphoma 5 protein (BCL-5), zinc finger and BTB domain-containing protein 27 (ZBTB27), protein LAZ-3, or zinc finger protein 51 (ZNF51). It is a transcriptional repressor mainly required for germinal center (GC) formation and antibody affinity maturation, which have different mechanisms of action specific to the lineage and biological functions. It represses its target genes by binding directly to the DNA sequence 5'-TTCCTAGAA-3' or indirectly by repressing the transcriptional activity of transcription factors. It contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*...
gi 24641603 140 VTADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:cd18331  71 INPEGFNILLDFMYTSRLNLREGNIMAVMATAMYLQMEHVVDTCRKFI 118

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in B-cell lymphoma 6 proteins, BCL-6 and BCL-6B; This family includes B-cell lymphoma 6 proteins, BCL-6 and BCL-6B. BCL-6 is a transcriptional repressor mainly required for germinal center (GC) formation and antibody affinity maturation, which have different mechanisms of action specific to the lineage and biological functions. BCL-6B is a sequence-specific transcriptional repressor in association with BCL-6. It may function in a narrow stage or be related to some events in the early B-cell development. Family members contain a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*
gi 24641603 142 ADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSF 186
Cdd:cd18215  68 PEGFRILLDFMYTSRLNLREGNIMAVMATAMYLQMEHVVDTCRKF 112

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 15 (KLHL15); KLHL15 is a substrate-specific adaptor for the Cullin3 E3 ubiquitin-protein ligase complex that targets the serine/threonine-protein phosphatase 2A (PP2A) subunit PPP2R5B for ubiquitination and subsequent proteasomal degradation, thus promoting exchange with other regulatory subunits. It also plays a key role in DNA damage response, favoring DNA double-strand repair through error-prone non-homologous end joining (NHEJ) over error-free, RBBP8-mediated homologous recombination (HR), by targeting the DNA-end resection factor RBBP8/CtIP for ubiquitination and subsequent proteasomal degradation. KLHL15 contains a BTB domain and kelch repeats, 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        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 24641603 135 LYLSNVTADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:cd18244  72 IHLKGLTATGFSHVLQFMYYGTIELSMLTVHEILQAAMYVQLTEVVKFCCSFL 124

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 5 (ZBTB5); ZBTB5 is a POZ domain Kruppel-like zinc finger (POK) family transcription repressor of cell cycle arrest gene p21 and a potential proto-oncogene stimulating cell proliferation. ZBTB5 contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*...
gi 24641603 140 VTADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:cd18196  70 VTAEAFAALIDMMYTSTLMLGESNVMDVLLAASHLHLNSVVKACKHYL 117

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 24641603 140 VTADQFAPLLTYMYTGYLDLNVDNIFAVLLATHVLHMPRALEICRSFL 187
Cdd:cd18956  71 VTAPAFGRLLDFMYEGRLDLRSLPVEDVLAAASYLHMYDIVKVCKGRL 118

zinc finger;

                           10        20
                   ....*....|....*....|...
gi 24641603    573 YVCVYCKHTFKSQYCYQKHAKRH 595
Cdd:smart00355   1 YRCPECGKVFKSKSALREHMRTH 23