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 32564072 133 QIVTINVSGMRFQTFESTLSRYPNSLLGDRNKRQHFFVSDTNEFFFDRHRTTsssftfeirnylFESILYIYQSGGRVKR 212
Cdd:cd18377   1 ERVVINVSGLRFETQLKTLAQFPNTLLGDPNKRMRFFDPLRNEYFFDRNRPS------------FDAILYYYQSGGRLRR 68

                        90
                ....*....|....*..
gi 32564072 213 PEIVPIDIFLKEMRFFQ 229
Cdd:cd18377  69 PVNVPLDIFLEEIRFYE 85

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNA/Kv1 subfamily of Shaker-type voltage-dependent potassium channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv1, also known as subfamily A, contains eight alpha subunit members, Kv1.1 (KCNA1), Kv1.2 (KCNA2), Kv1.3 (KCNA3), Kv1.4 (KCNA4), Kv1.5 (KCNA5), Kv1.6 (KCNA6), Kv1.7 (KCNA7), and Kv1.8 (KCNA10), which are orthologs of the Shaker gene in Drosophila. They are delayed rectifiers except for Kv1.4 (KCNA4), which is an A-type potassium channel. Delayed rectifiers are slow opening and closing voltage-gated potassium channels. Because of their delayed activation kinetics, they play an important role in controlling action potential duration. A-type channels are fast/rapidly inactivating potassium channels. Kv1/KCNA subfamily alpha subunits form functional homo- or hetero-tetrameric channels (with other Kv1/KCNA alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 133 QIVTINVSGMRFQTFESTLSRYPNSLLGDRNKRQHFFVSDTNEFFFDRHRTTsssftfeirnylFESILYIYQSGGRVKR 212
Cdd:cd18377   1 ERVVINVSGLRFETQLKTLAQFPNTLLGDPNKRMRFFDPLRNEYFFDRNRPS------------FDAILYYYQSGGRLRR 68

                        90
                ....*....|....*..
gi 32564072 213 PEIVPIDIFLKEMRFFQ 229
Cdd:cd18377  69 PVNVPLDIFLEEIRFYE 85

BTB/POZ domain; In voltage-gated K+ channels this domain is responsible for subfamily-specific assembly of alpha-subunits into functional tetrameric channels. In KCTD1 this domain functions as a transcriptional repressor. It also mediates homomultimerization of KCTD1 and interaction of KCTD1 with the transcription factor AP-2-alpha.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072   135 VTINVSGMRFQTFESTLSRYPNSLLGDRNKR-QHFFVSDTNEFFFDRHRTtsssftfeirnyLFESILYIYQSGGRVKRP 213
Cdd:pfam02214   1 VKLNVGGTRFETLKSTLTRFPDTRLGRLLELeCDDYDDDTNEYFFDRSPK------------HFETILNFYRTGGKLHRP 68

                          90       100
                  ....*....|....*....|....*
gi 32564072   214 EIVPIDIFLKEMRFFQMGDDLLEEF 238
Cdd:pfam02214  69 EEVCLDEFLEEAEFYGLDELALELC 93

voltage-gated potassium channel protein;

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 32564072  436 ALVLFASGMYFAEQG------EPNSKFTSIPASFWFVLVTMTTVGYGDLVPLSP 483
Cdd:PRK10537 140 AVISITSLLFYSTFGalylgdGFSPPIESLSTAFYFSIVTMSTVGYGDIVPVSE 193

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNA/Kv1 subfamily of Shaker-type voltage-dependent potassium channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv1, also known as subfamily A, contains eight alpha subunit members, Kv1.1 (KCNA1), Kv1.2 (KCNA2), Kv1.3 (KCNA3), Kv1.4 (KCNA4), Kv1.5 (KCNA5), Kv1.6 (KCNA6), Kv1.7 (KCNA7), and Kv1.8 (KCNA10), which are orthologs of the Shaker gene in Drosophila. They are delayed rectifiers except for Kv1.4 (KCNA4), which is an A-type potassium channel. Delayed rectifiers are slow opening and closing voltage-gated potassium channels. Because of their delayed activation kinetics, they play an important role in controlling action potential duration. A-type channels are fast/rapidly inactivating potassium channels. Kv1/KCNA subfamily alpha subunits form functional homo- or hetero-tetrameric channels (with other Kv1/KCNA alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 133 QIVTINVSGMRFQTFESTLSRYPNSLLGDRNKRQHFFVSDTNEFFFDRHRTTsssftfeirnylFESILYIYQSGGRVKR 212
Cdd:cd18377   1 ERVVINVSGLRFETQLKTLAQFPNTLLGDPNKRMRFFDPLRNEYFFDRNRPS------------FDAILYYYQSGGRLRR 68

                        90
                ....*....|....*..
gi 32564072 213 PEIVPIDIFLKEMRFFQ 229
Cdd:cd18377  69 PVNVPLDIFLEEIRFYE 85

Ion transport protein; This family contains sodium, potassium and calcium ion channels. This family is 6 transmembrane helices in which the last two helices flank a loop which determines ion selectivity. In some sub-families (e.g. Na channels) the domain is repeated four times, whereas in others (e.g. K channels) the protein forms as a tetramer in the membrane.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072   274 ARIIAFISIAVIALSIISFCWETVPsdieekpinnsataelldEMDEKHYSPFFWIELMCILWFTIELILRFISCPCKVT 353
Cdd:pfam00520   1 SRYFELFILLLILLNTIFLALETYF------------------QPEEPLTTVLEILDYVFTGIFTLEMLLKIIAAGFKKR 62

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072   354 FATSVLNIIDFVAIAPFFVNFFfadtskSNSSMSFAVLRVLRLVRVFRVFKLSRHSVGLQILGKTFRSSVQEFCLLIFFM 433
Cdd:pfam00520  63 YFRSPWNILDFVVVLPSLISLV------LSSVGSLSGLRVLRLLRLLRLLRLIRRLEGLRTLVNSLIRSLKSLGNLLLLL 136

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072   434 AIALVLFASGMY---------FAEQGEPNSKFTSIPASFWFVLVTMTTVGYGDLVPLSPFGKVVGGMCAM-------IGV 497
Cdd:pfam00520 137 LLFLFIFAIIGYqlfggklktWENPDNGRTNFDNFPNAFLWLFQTMTTEGWGDIMYDTIDGKGEFWAYIYfvsfiilGGF 216

                         250       260
                  ....*....|....*....|..
gi 32564072   498 LTLALPVPIIVANFKHFYRQEN 519
Cdd:pfam00520 217 LLLNLFIAVIIDNFQELTERTE 238

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 7 (KCNA7); KCNA7, also called voltage-gated potassium channel subunit Kv1.7, mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. KCNA7 plays an important role in the repolarization of cell membranes. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNA7 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 135 VTINVSGMRFQTFESTLSRYPNSLLGDRNKRQHFFVSDTNEFFFDRHRTTsssftfeirnylFESILYIYQSGGRVKRPE 214
Cdd:cd18408   8 VVLNVAGLRFETRARTLGRFPDTLLGDPARRGRFYDDRRREYFFDRHRPS------------FDAVLYYYQSGGRLRRPA 75

                        90       100       110
                ....*....|....*....|....*....|....*....
gi 32564072 215 IVPIDIFLKEMRFFQMGDDLLEEFWIAEGYEKPKEVMMP 253
Cdd:cd18408  76 HVPLDVFLEEVAFYGLGAAALARLREDEGCPVPPERPLP 114

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shaker and similar proteins; Shaker, also termed protein minisleep, represents a family of putative potassium channel proteins in the nervous system of Drosophila. It is a voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Shaker plays a role in the regulation of sleep need or efficiency. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. Shaker is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 135 VTINVSGMRFQTFESTLSRYPNSLLGDRNKRQHFFVSDTNEFFFDRHRTTsssftfeirnylFESILYIYQSGGRVKRPE 214
Cdd:cd18410   3 VVINVSGLRFETQLKTLNQFPDTLLGDPQRRNRYYDPLRNEYFFDRNRPS------------FDAILYYYQSGGRLRRPV 70

                        90       100       110
                ....*....|....*....|....*....|
gi 32564072 215 IVPIDIFLKEMRFFQMGDDLLEEFWIAEGY 244
Cdd:cd18410  71 NVPLDVFSEEIKFYELGENAFEKYREDEGF 100

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 5 (KCNA5); KCNA5, also called HPCN1, voltage-gated potassium channel HK2, or voltage-gated potassium channel subunit Kv1.5, mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. KCNA5 may play a role in regulating the secretion of insulin in normal pancreatic islets. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNA5 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 133 QIVTINVSGMRFQTFESTLSRYPNSLLGDRNKRQHFFVSDTNEFFFDRHRTTsssftfeirnylFESILYIYQSGGRVKR 212
Cdd:cd18406   1 ERVIINIAGLRFETQLGTLNQFPDTLLGDPDKRMRYFDPLRNEYFFDRNRPS------------FDGILYFYQSGGKIRR 68

                        90       100
                ....*....|....*....|....*.
gi 32564072 213 PEIVPIDIFLKEMRFFQMGDDLLEEF 238
Cdd:cd18406  69 PVNVSIDVFADEIRFYQLGEEAMERF 94

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 1 (KCNA1); KCNA1 is also called voltage-gated K(+) channel HuKI, voltage-gated potassium channel HBK1, or voltage-gated potassium channel subunit Kv1.1. It mediates transmembrane potassium transport in excitable membranes, primarily in the brain and the central nervous system, but also in the kidney. It is involved in the regulation of the membrane potential and nerve signaling, and prevents neuronal hyperexcitability. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNA1 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 135 VTINVSGMRFQTFESTLSRYPNSLLGDRNKRQHFFVSDTNEFFFDRHRTTsssftfeirnylFESILYIYQSGGRVKRPE 214
Cdd:cd18402  11 VVINIAGLRFETQLKTLAQFPNTLLGNPKKRMRYFDPLRNEYFFDRNRPS------------FDAILYYYQSGGRLRRPV 78

                        90
                ....*....|....*....
gi 32564072 215 IVPIDIFLKEMRFFQMGDD 233
Cdd:cd18402  79 NVPLDMFSEEIKFYELGEE 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 1 (KCND1); KCND1, also called voltage-gated potassium channel subunit Kv4.1, is a pore-forming subunit of voltage-gated rapidly inactivating A-type potassium channels. It may contribute to I (To) current in heart and I (Sa) current in neurons. Its properties are modulated by interactions with other alpha subunits and with regulatory subunits. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCND1 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv4/KCND alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. It is modulated by cytoplasmic KChIPs/KCNIPs (Kv-channel interacting proteins), which are small calcium binding proteins with EF-hand-like domains.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 112 LPSPQRGTPDTSSTQGHpYTDQIVTINVSGMRFQTFESTLSRYPNSLLGDRNKrQHFFVSDTNEFFFDRHRTtsssftfe 191
Cdd:cd18417  15 LPLAKKPMPKPPSDKKR-RNDEILVVNVSGRRFQTWKNTLDRYPDTLLGSSEK-EFFYNEDTQEYFFDRDPE-------- 84

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|..
gi 32564072 192 irnyLFESILYIYQSgGRVKRPEIVPIDIFLKEMRFFQM-----GDDLLEEF 238
Cdd:cd18417  85 ----MFRHILNFYRT-GRLHYPRHECIQAFDEELSFYGIipeiiGDCCLEEY 131

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCND/Kv4 subfamily of Shal-type voltage-dependent potassium channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv4, also known as subfamily D, contains three alpha subunit members, Kv4.1 (KCND1), Kv4.2 (KCND2), and Kv4.3 (KCND3), which are orthologs of the Shal gene in Drosophila. They are A-type potassium channels that mediate the native, fast inactivating (A-type) K+ current (IA) described both in the nervous system (A currents) and the heart (transient outward current). Kv4/KCND subfamily alpha subunits form functional homo- or hetero-tetrameric channels through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. They are modulated by cytoplasmic KChIPs/KCNIPs (Kv-channel interacting proteins), which are small calcium binding proteins with EF-hand-like domains.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 135 VTINVSGMRFQTFESTLSRYPNSLLGDrNKRQHFFVSDTNEFFFDRHRTtsssftfeirnyLFESILYIYQSgGRVKRPE 214
Cdd:cd18380   2 IVINVSGRRFETWKNTLEKYPDTLLGS-TEKEFFYDDDTKEYFFDRDPE------------IFRHILNFYRT-GKLHYPR 67

                        90       100
                ....*....|....*....|.
gi 32564072 215 IVPIDIFLKEMRFFQMGDDLL 235
Cdd:cd18380  68 HECISAYDDELAFFGILPEII 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 2 (KCND2); KCND2, also called voltage-gated potassium channel subunit Kv4.2, is a major pore-forming subunit in somatodendritic subthreshold A-type potassium current I(SA) channels. It mediates transmembrane potassium transport in excitable membranes, primarily in the brain. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCND2 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv4/KCND alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. It is modulated by cytoplasmic KChIPs/KCNIPs (Kv-channel interacting proteins), which are small calcium binding proteins with EF-hand-like domains.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 134 IVTINVSGMRFQTFESTLSRYPNSLLGDrNKRQHFFVSDTNEFFFDRHRTtsssftfeirnyLFESILYIYQSgGRVKRP 213
Cdd:cd18418   1 LIVLNVSGTRFQTWRNTLERYPDTLLGS-SERDFFYHEETQEYFFDRDPD------------IFRHILNFYRT-GKLHYP 66

                        90       100       110
                ....*....|....*....|....*....|
gi 32564072 214 EIVPIDIFLKEMRFFQM-----GDDLLEEF 238
Cdd:cd18418  67 RHECISAYDEELAFFGIipeiiGDCCYEEY 96

Ion channel; This family includes the two membrane helix type ion channels found in bacteria.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 32564072   432 FMAIALVLFASGMYFAEQGEPNSKFTSipasFWFVLVTMTTVGYGDLVPLSPFGKVVGGMCAMIGVLTLALPVPIIV 508
Cdd:pfam07885   1 IVLLLVLIFGTVYYLLEEGWEWSFLDA----LYFSFVTLTTVGYGDIVPLTDAGRLFTIFYILIGIPLFAIFLAVLG 73

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins; The potassium channel tetramerization domain (KCTD) family proteins contain the BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels and others. Some KCTD proteins are involved in protein ubiquitination as part of the CRL (Cullin RING Ligase) E3 ligases. Some others show Cullin-independent functions including binding and regulation of GABA (gamma-aminobutyric acid) receptors (KCTD8, KCTD12 and KCTD16) and inhibition of AP-2 function (KCTD15). KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 135 VTINVSGMRFQTFESTLSRYPNSLLGDR-NKRQHFFVSDTNEFFFDRhrttSSSftfeirnyLFESILYIYQSGGRVKRP 213
Cdd:cd18316   1 VKLNVGGTLFTTSRSTLLKDPDSLLAALfSGRWPLPRDEDGSIFIDR----DPE--------LFRHILNFLRTGKLPLPS 68

                        90
                ....*....|....*
gi 32564072 214 EIVPIDIFLKEMRFF 228
Cdd:cd18316  69 DFVELEELLAEAEFY 83

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 32564072    135 VTINVSGMRFQTFESTLSRYPNSLLgDRNKRQHFFVSDTNEFFFDRHRTTsssftfeirnylFESILYIYQSgGRVKRPE 214
Cdd:smart00225   2 VTLVVGGKKFHAHKAVLAAHSPYFK-ALFSSDFKESDKSEIYLDDVSPED------------FRALLNFLYT-GKLDLPE 67

                           90       100
                   ....*....|....*....|....*.
gi 32564072    215 iVPIDIFLKEMRFFQMGD--DLLEEF 238
Cdd:smart00225  68 -ENVEELLELADYLQIPGlvELCEEF 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel protein Shaw; Shaw, also called Shaw2, is a voltage-gated potassium channel in Drosophila. It mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. Shaw is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 132 DQIVTINVSGMRFQTFESTLSRYPNSLLGDRNKRQHFFVSDTNEFFFDRHRTtsssftfeirnyLFESILYIYQSgGRVK 211
Cdd:cd18416   1 ENRVVLNVGGIRHETYKATLKKIPATRLSRLTEALANYDPVLNEYFFDRHPG------------VFAQILNYYRT-GKLH 67

                        90       100
                ....*....|....*....|....*
gi 32564072 212 RPEIVPIDIFLKEMRFFQMGDDLLE 236
Cdd:cd18416  68 YPTDVCGPLFEEELEFWGLDANQVE 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily C members KCNC1 and KCNC3; KCNC1 (also called NGK2, voltage-gated potassium channel subunit Kv3.1, or voltage-gated potassium channel subunit Kv4) and KCNC3 (also called KSHIIID or voltage-gated potassium channel subunit Kv3.3) play important roles in the rapid repolarization of fast-firing brain neurons. Assuming opened or closed conformations in response to the voltage difference across the membrane, the proteins form tetrameric potassium-selective channels through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNC1 and KCNC3 are alpha subunit that form functional homo- or hetero-tetrameric channels (with other alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 131 TDQIVtINVSGMRFQTFESTLSRYPN---SLLGDRNKRQHF-FVSDTNEFFFDRHRTtsssftfeirnyLFESILYIYQS 206
Cdd:cd18414   2 SDRIV-INVGGTRHETYRSTLRTLPGtrlAWLAEPDAHSNFdYDPRADEFFFDRHPG------------VFAHILNYYRT 68

                        90       100
                ....*....|....*....|..
gi 32564072 207 gGRVKRPEIVPIDIFLKEMRFF 228
Cdd:cd18414  69 -GKLHCPADVCGPLYEEELAFW 89

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 6 (KCTD6); KCTD6, also called KCTD containing, Cullin3 adaptor, suppressor of Hedgehog 3 (KCASH3), is a BTB/POZ domain-containing protein that functions as a substrate-specific adaptor of cullin-3, regulating protein levels of the muscle small ankyrin-1 isoform 5 (sAnk1.5) as well as suppressing histone deacetylase and Hedgehog activity in medulloblastoma. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

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gi 32564072 135 VTINVSGMRFQTFESTLSRYPNSLLGdrnkrqHFFVSDtneffFDRHRTTSSSFTFEIRNYLFESILYIYQSGGRVKRPE 214
Cdd:cd18394   5 VTLNVGGHLYTTSLSTLTRYPDSMLG------AMFRGD-----FPTARDSQGNYFIDRDGPLFRYILNFLRTSELTLPVD 73

                        90
                ....*....|....*.
gi 32564072 215 IVPIDIFLKEMRFFQM 230
Cdd:cd18394  74 FKEFDLLRKEADFYQI 89

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 7 (KCTD7); KCTD7 is a BTB/POZ domain-containing protein that has an impact on K+ fluxes, neurotransmitter synthesis, and neuronal function. It functions as a regulator of potassium conductance in neurons, and is involved in the control of excitability of cortical neurons. Mutations in KCTD7 may cause progressive myoclonus epilepsy (PME). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

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                ....*....|....*....|....*....|....*....|....*...
gi 32564072 134 IVTINVSGMRFQTFESTLSRYPNSLLGDRNKRQHFFVSDTN-EFFFDR 180
Cdd:cd18366   5 VVPLNVGGMHFTTRLSTLRKYEDSMLAAMFSGRHHIPKDSEgRYFIDR 52

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily V member 1 (KCNV1); KCNV1, also called neuronal potassium channel alpha subunit HNKA or voltage-gated potassium channel subunit Kv8.1, is a new neuronal voltage-gated potassium channel alpha subunit with specific inhibitory properties towards Shab and Shaw channels. It modulates KCNB1 (also known as Kv2.1) and KCNB2 (also known as Kv2.2) channel activity by shifting the threshold for inactivation to more negative values and by slowing the rate of inactivation. It can also down-regulate the channel activity of KCNB1, KCNB2, KCNC4 (also known as Kv3.4) and KCND1 (also known as Kv4.1), possibly by trapping them in intracellular membranes. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNV1 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

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                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 32564072 136 TINVSGMRFQTFESTLSRYPNSLLGDRNKRQHFFVSD--------TNEFFFDRHRTTsssftfeirnylFESILYIYQSG 207
Cdd:cd18424   2 TINVGGSRFVLSQQVLSSHPETRLGKLAVSVRDSVLElcddanfvDNEYFFDRSSQA------------FKYIMNYYKTG 69

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                ....*....|....*....|....*....|....*....|..
gi 32564072 208 GRVKRPEIVPIDiFLKEMRFFQMgDDLLEEFWIAEGYEKPKE 249
Cdd:cd18424  70 HLHVMEELCAIS-FLQEIEYWGI-DELSIDSCCRERYYRRKE 109

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNG/Kv6 subfamily of potassium voltage-gated channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv6, also known as subfamily G, includes KCNG1 (Kv6.1), KCNG2 (Kv6.2 or KCNF2), KCNG3 (Kv6.3) and KCNG4 (Kv6.4), which are regulatory alpha subunits and do not form functional channels on their own. KCNG1 can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1. KCNG2, also called cardiac potassium channel subunit, can form functional heterodimeric channels with KCNB1, and further modulates channel activity by shifting the threshold and the half-maximal activation to more negative values. KCNG3, also called voltage-gated potassium channel subunit Kv10.1, is an electrically silent modulatory subunit that can form functional heterotetrameric channels with KCNB1, and further promotes a reduction in the rate of activation and inactivation of the delayed rectifier voltage-gated potassium channel KCNB1. KCNG4 is a silent voltage-gated potassium (KvS) channel subunit that can form functional heterotetrameric channels with KCNB1, and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1.

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                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 32564072 135 VTINVSGMRFQTFESTLSRYPNSLLGD----RNKRQHFFVSD-----TNEFFFDRHrttSSSFTFeIRNYL 196
Cdd:cd18382   1 VIINVGGARYSLPWSTLDRFPLTRLSRlkacRSEDDILRVCDdydveRNEFFFDRS---PEAFGV-ILLFL 67