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 9790093    6 AAWLPFARAAAIGWMPVASGPMPAPPRQERKRtQDALIVLNVSGTRFQTWQDTLERYPDTLLGSSERDFFYHPETQQYFF 85
Cdd:cd18419   1 AAWLPFARAAAIGWMPVANCPMPLAPADKNKR-QDELIVLNVSGRRFQTWRTTLERYPDTLLGSTEKEFFFNEDTKEYFF 79

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 9790093   86 DRDPDIFRHILNFYRTGKLHYPRHECISAYDEELAFFGLIPEIIGDCCYEEYKDRRREN 144
Cdd:cd18419  80 DRDPEVFRCVLNFYRTGKLHYPRYECISAYDEELAFYGILPEIIGDCCYEEYKDRKREN 138

Domain of unknown function (DUF3399); This domain is functionally uncharacterized. This domain is found in eukaryotes. This presumed domain is about 100 amino acids in length. This domain is found associated with pfam02214, pfam00520.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 9790093    470 SGSSFETQHHHLLHCLEKTTNHEFVDEQVFEESCMEVATVNRpSSHSPSLSSQQGVTSTCCSRRHKKTFRIPNANVS 546
Cdd:pfam11879   1 STSLFESQHHHLLHCLEKTTNHEFVDEQTYEQNCLEVSLQNR-PSRSPSLSSQDGLTSSCCSRRAKRNTRLPNSSVP 76

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 3 (KCND3); KCND3, also called voltage-gated potassium channel subunit Kv4.3, is a pore-forming subunit of voltage-gated rapidly inactivating A-type potassium channels. Mutations in KCND3 cause spinocerebellar ataxia. 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. KCND3 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 9790093    6 AAWLPFARAAAIGWMPVASGPMPAPPRQERKRtQDALIVLNVSGTRFQTWQDTLERYPDTLLGSSERDFFYHPETQQYFF 85
Cdd:cd18419   1 AAWLPFARAAAIGWMPVANCPMPLAPADKNKR-QDELIVLNVSGRRFQTWRTTLERYPDTLLGSTEKEFFFNEDTKEYFF 79

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 9790093   86 DRDPDIFRHILNFYRTGKLHYPRHECISAYDEELAFFGLIPEIIGDCCYEEYKDRRREN 144
Cdd:cd18419  80 DRDPEVFRCVLNFYRTGKLHYPRYECISAYDEELAFYGILPEIIGDCCYEEYKDRKREN 138

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 9790093     43 IVLNVSGTRFQTWQDTLERYPDTLLGS--SERDFFYHPETQQYFFDRDPDIFRHILNFYRT-GKLHYPRHECISAYDEEL 119
Cdd:pfam02214   1 VKLNVGGTRFETLKSTLTRFPDTRLGRllELECDDYDDDTNEYFFDRSPKHFETILNFYRTgGKLHRPEEVCLDEFLEEA 80

                          90
                  ....*....|...
gi 9790093    120 AFFGLIPEIIGDC 132
Cdd:pfam02214  81 EFYGLDELALELC 93

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 9790093      43 IVLNVSGTRFQTWQDTLERYPDTLLGSSERDFFYHPETQQYFFDRDPDIFRHILNFYRTGKLHYPRhECISAYDEELAFF 122
Cdd:smart00225   2 VTLVVGGKKFHAHKAVLAAHSPYFKALFSSDFKESDKSEIYLDDVSPEDFRALLNFLYTGKLDLPE-ENVEELLELADYL 80

                           90
                   ....*....|....*...
gi 9790093     123 gLIPEIIGDCCYEEYKDR 140
Cdd:smart00225  81 -QIPGLVELCEEFLLKLL 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 3 (KCND3); KCND3, also called voltage-gated potassium channel subunit Kv4.3, is a pore-forming subunit of voltage-gated rapidly inactivating A-type potassium channels. Mutations in KCND3 cause spinocerebellar ataxia. 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. KCND3 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 9790093    6 AAWLPFARAAAIGWMPVASGPMPAPPRQERKRtQDALIVLNVSGTRFQTWQDTLERYPDTLLGSSERDFFYHPETQQYFF 85
Cdd:cd18419   1 AAWLPFARAAAIGWMPVANCPMPLAPADKNKR-QDELIVLNVSGRRFQTWRTTLERYPDTLLGSTEKEFFFNEDTKEYFF 79

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 9790093   86 DRDPDIFRHILNFYRTGKLHYPRHECISAYDEELAFFGLIPEIIGDCCYEEYKDRRREN 144
Cdd:cd18419  80 DRDPEVFRCVLNFYRTGKLHYPRYECISAYDEELAFYGILPEIIGDCCYEEYKDRKREN 138

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 9790093    6 AAWLPFARAAAIGWMPVASGPMPAPPRQERKRTqDALIVLNVSGTRFQTWQDTLERYPDTLLGSSERDFFYHPETQQYFF 85
Cdd:cd18417   1 ATWLPFARAAAVGWLPLAKKPMPKPPSDKKRRN-DEILVVNVSGRRFQTWKNTLDRYPDTLLGSSEKEFFYNEDTQEYFF 79

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 9790093   86 DRDPDIFRHILNFYRTGKLHYPRHECISAYDEELAFFGLIPEIIGDCCYEEYKDRRREN 144
Cdd:cd18417  80 DRDPEMFRHILNFYRTGRLHYPRHECIQAFDEELSFYGIIPEIIGDCCLEEYRDRKKEN 138

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 9790093   42 LIVLNVSGTRFQTWQDTLERYPDTLLGSSERDFFYHPETQQYFFDRDPDIFRHILNFYRTGKLHYPRHECISAYDEELAF 121
Cdd:cd18380   1 RIVINVSGRRFETWKNTLEKYPDTLLGSTEKEFFYDDDTKEYFFDRDPEIFRHILNFYRTGKLHYPRHECISAYDDELAF 80

                        90       100
                ....*....|....*....|..
gi 9790093  122 FGLIPEIIGDCCYEEYKDRRRE 143
Cdd:cd18380  81 FGILPEIIGDCCYEDYRDRKRE 102

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 9790093     43 IVLNVSGTRFQTWQDTLERYPDTLLGS--SERDFFYHPETQQYFFDRDPDIFRHILNFYRT-GKLHYPRHECISAYDEEL 119
Cdd:pfam02214   1 VKLNVGGTRFETLKSTLTRFPDTRLGRllELECDDYDDDTNEYFFDRSPKHFETILNFYRTgGKLHRPEEVCLDEFLEEA 80

                          90
                  ....*....|...
gi 9790093    120 AFFGLIPEIIGDC 132
Cdd:pfam02214  81 EFYGLDELALELC 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in voltage-gated potassium (Kv) channels and potassium channel tetramerization domain-containing (KCTD) proteins; This family includes two protein groups: voltage-gated potassium (Kv) channels and potassium channel tetramerization domain-containing (KCTD) proteins. Kv channels are membrane proteins with fundamental physiological roles. They are responsible for a variety of electrical phenomena, such as the repolarization of the action potential, spike frequency adaptation, synaptic repolarization, and smooth muscle contraction. 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. All family members contain the BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGS---SERDFFYHPETQQYFFDRDPDIFRHILNFYRTGKLHYPRHECISAYDEEL 119
Cdd:cd18187   1 VVLNVSGTRFVTNRQTLTRHPDTLLGRmfkPGREFTFPNETGEYFIDRDPTVFRTILNYYRTGKLNCPDGISIPDLREEC 80

                ...
gi 9790093  120 AFF 122
Cdd:cd18187  81 DFY 83

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNC/Kv3 subfamily of Shaw-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 Kv3, also known as subfamily C, contains four alpha subunit members, Kv3.1 (KCNC1), Kv3.2 (KCNC2), Kv3.3 (KCNC3), and Kv3.4 (KCNC4), which are orthologs of the Shaw gene in Drosophila. Unlike other Kv subfamilies, Kv3 channels typically open only at positive potentials and both, activation and deactivation, in response to changes in voltage are very rapid. They are uniquely associated with the ability of certain neurons to fire action potentials and to release neurotransmitter at high rates of up to 1,000 Hz. Kv3/KCNC subfamily alpha subunits 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 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGS----SERDFFYHPETQQYFFDRDPDIFRHILNFYRTGKLHYPRHECISAYDEE 118
Cdd:cd18379   1 IVINVGGVRHETYKSTLRNLPDTRLAWltetEASAFDYDPVTGEFFFDRHPGVFAQILNYYRTGKLHCPADVCGPLFEEE 80

                        90       100
                ....*....|....*....|...
gi 9790093  119 LAFFGLIPEIIGDCCYEEYKDRR 141
Cdd:cd18379  81 LAFWGIDETQIEPCCWMTYRQHR 103

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 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGS-SERDFFYHPETQQYFFDRDPDIFRHILNFYRTGKLHYPRHECISAYDEELAF 121
Cdd:cd18416   4 VVLNVGGIRHETYKATLKKIPATRLSRlTEALANYDPVLNEYFFDRHPGVFAQILNYYRTGKLHYPTDVCGPLFEEELEF 83

                        90       100
                ....*....|....*....|
gi 9790093  122 FGLIPEIIGDCCYEEYKDRR 141
Cdd:cd18416  84 WGLDANQVEPCCWMTYTAHR 103

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily C members KCNC2 and KCNC4; KCNC2, also called Shaw-like potassium channel or voltage-gated potassium channel Kv3.2, is a delayed rectifier voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain. It contributes to the regulation of the fast action potential repolarization and in sustained high-frequency firing in neurons of the central nervous system. KCNC4, also called KSHIIIC or voltage-gated potassium channel subunit Kv3.4, is a novel high-voltage-activating, tetraethylammonium (TEA)-sensitive, type-A potassium channel that mediates the voltage-dependent potassium ion permeability of excitable membranes. It plays a pivotal role in oxidative stress-related neural cell damage as an oxidation-sensitive channel. 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. KCNC2 and KCNC4 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 9790093   43 IVLNVSGTRFQTWQDTLERYPDT---LLGSSE-------------RDFFYHPETQQYFFDRDPDIFRHILNFYRTGKLHY 106
Cdd:cd18415   4 IILNVGGTRHETYRSTLKTLPGTrlaLLASSDpqgdcltqcsqvgGSDGSPGGGNEFFFDRHPGVFAYVLNYYRTGKLHC 83

                        90       100       110
                ....*....|....*....|....*....|....*
gi 9790093  107 PRHECISAYDEELAFFGLIPEIIGDCCYEEYKDRR 141
Cdd:cd18415  84 PADVCGPLFEEELAFWGIDETDVEPCCWMTYRQHR 118

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 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGSSE-RDFFYHPETQQYFFDRDPDIFRHILNFYRT-GKLHYPRHECISAYDEELA 120
Cdd:cd18377   3 VVINVSGLRFETQLKTLAQFPNTLLGDPNkRMRFFDPLRNEYFFDRNRPSFDAILYYYQSgGRLRRPVNVPLDIFLEEIR 82

                ..
gi 9790093  121 FF 122
Cdd:cd18377  83 FY 84

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
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGS--SERDFFYHPETQQYFFDRDPDIFRHILNFYRTGKLHYPRHE 110
Cdd:cd18316   1 VKLNVGGTLFTTSRSTLLKDPDSLLAAlfSGRWPLPRDEDGSIFIDRDPELFRHILNFLRTGKLPLPSDF 70

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 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGS-SERDFFYHPETQQYFFDRDPDIFRHILNFYRT-GKLHYPRHECISAYDEELA 120
Cdd:cd18408   8 VVLNVAGLRFETRARTLGRFPDTLLGDpARRGRFYDDRRREYFFDRHRPSFDAVLYYYQSgGRLRRPAHVPLDVFLEEVA 87

                        90
                ....*....|
gi 9790093  121 FFGLIPEIIG 130
Cdd:cd18408  88 FYGLGAAALA 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 6 (KCNA6); KCNA6, also called voltage-gated potassium channel HBK2 or voltage-gated potassium channel subunit Kv1.6, 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. KCNA6 is distributed primarily in neurons of central and peripheral nervous systems. 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. KCNA6 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 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGS-SERDFFYHPETQQYFFDRDPDIFRHILNFYRT-GKLHYPRHECISAYDEELA 120
Cdd:cd18407   3 LVINISGLRFETQLRTLSIFPDTLLGDpSRRVRYFDPLRNEYFFDRNRPSFDAILYYYQSgGRLRRPVHVPLDIFLEEIR 82

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 9790093  121 FFGLIPEIIgdccyeeykdrrrenaERLQDDADTDNTGESALPTMTARQRVWRAFENPHTS 181
Cdd:cd18407  83 FYQLGQEAI----------------ETFREDEGFIPEEEKPLPSHHFQRQVWLLFEYPESS 127

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.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLG-----SSERDFF-----YHPETQQYFFDRDPDIFRHILNFYRTGKLHYPRHECI 112
Cdd:cd18382   1 VIINVGGARYSLPWSTLDRFPLTRLSrlkacRSEDDILrvcddYDVERNEFFFDRSPEAFGVILLFLRAGKLRLLREMCA 80

                        90       100
                ....*....|....*....|....*...
gi 9790093  113 SAYDEELAFFGLIPEIIGDCCYEEYKDR 140
Cdd:cd18382  81 LSFQEELAYWGIEEAHLERCCKRRLLRR 108

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNF/Kv5 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 Kv5, also known as subfamily F, only contains KCNF1 (also known as Kv5.1 or kH1), which functions as a regulatory alpha-subunit of voltage-gated potassium channel that when coassembled with Kv2.1 can modulate gating in a physiologically relevant manner. It forms 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 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLL-------GSSERDFF-----YHPETQQYFFDRDPDIFRHILNFYRTGKLHYPRHE 110
Cdd:cd18381   3 IVVNVGGVRQVLYGDVLNRYPETRLaellnclSGGYDAIFslcddYDPGKREFYFDRDPDAFKCIIEVYYYGEIHMKKGI 82

                        90       100       110
                ....*....|....*....|....*....|...
gi 9790093  111 CISAYDEELAFFGLIPEIIGDCCYEEYKDRRRE 143
Cdd:cd18381  83 CPICFKNEMDFWRVDLDFLDECCKCHLSEKREE 115

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A members 2 (KCNA2) and 3 (KCNA3); KCNA2 is also called NGK1, voltage-gated K(+) channel HuKIV, voltage-gated potassium channel HBK5, or voltage-gated potassium channel subunit Kv1.2. KCNA3 is also called HGK5, HLK3, HPCN3, voltage-gated K(+) channel HuKIII, or voltage-gated potassium channel subunit Kv1.3. KCNA2 and KCNA3 mediate 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. KCNA2 primarily functions in the brain and the central nervous system, but also in the cardiovascular system. It prevents aberrant action potential firing and regulates neuronal output. 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. KCNA2 and KCNA3 are alpha subunits that 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 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGSSERDF-FYHPETQQYFFDRDPDIFRHILNFYRT-GKLHYPRHECISAYDEELA 120
Cdd:cd18403   3 VVINISGLRFETQLKTLAQFPETLLGDPKKRMrYFDPLRNEYFFDRNRPSFDAILYYYQSgGRLRRPVNVPLDIFSEEIR 82

                ....*....
gi 9790093  121 FFGLIPEII 129
Cdd:cd18403  83 FYELGEEAM 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily B member 2 (KCNB2); KCNB2, also called voltage-gated potassium channel subunit Kv2.2, mediates transmembrane potassium transport in excitable membranes, primarily in the brain and smooth muscle cells. 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. KCNB2 contributes to the delayed-rectifier voltage-gated potassium current in cortical pyramidal neurons and smooth muscle cells. 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. KCNB2 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 9790093   28 PAPPRQERKRTQDALIVLNVSGTRFQTWQDTLERYPDTLLGSSeRDFFYHPE-----------TQQYFFDRDPDIFRHIL 96
Cdd:cd18412   4 PEPVEIIRSKACSRRVKINVGGLNHEVLWRTLDRLPRTRLGKL-RDCNTHESllevcddynlnENEYFFDRHPGAFTSIL 82

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*
gi 9790093   97 NFYRTGKLHYPRHECISAYDEELAFFGLIPEIIGDCCYEEYKDRR 141
Cdd:cd18412  83 NFYRTGKLHMMEEMCALSFGQELDYWGIDEIYLESCCQARYHQKK 127

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

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9790093    331 LTMAIIIFATVMFYAEKGSSASKFTsipaAFWYTIVTMTTLGYGDMVPKTIAGKIFGSICSLSGVLVIALPVPVIVSNFS 410
Cdd:pfam07885   2 VLLLVLIFGTVYYLLEEGWEWSFLD----ALYFSFVTLTTVGYGDIVPLTDAGRLFTIFYILIGIPLFAIFLAVLGRFLT 77

                  .
gi 9790093    411 R 411
Cdd:pfam07885  78 E 78

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Arabidopsis thaliana FH protein interacting protein FIP2 and similar proteins; FIP2 may act as a substrate-specific adaptor of an E3 ubiquitin-protein ligase complex (CUL3-RBX1-BTB) which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGS--SERdffYHPETQQ---YFFDRDPDIFRHILNFYRTGKLHYPrHECISAYDE 117
Cdd:cd18376   1 VKLNVGGQKFTTTLDTLTKDPDSMLAAmfSGR---HSLKKDEdgsYFIDRDGTHFRHILNYLRDGEVKIP-TEDRSVLKE 76

                        90
                ....*....|
gi 9790093  118 ---ELAFFGL 124
Cdd:cd18376  77 lleEAEYYQL 86

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 4 (KCNA4); KCNA4 is also called HPCN2, or voltage-gated K(+) channel HuKII, voltage-gated potassium channel HBK4, voltage-gated potassium channel HK1, or voltage-gated potassium channel subunit Kv1.4. 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. KCNA4 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 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGSSE-RDFFYHPETQQYFFDRDPDIFRHILNFYRT-GKLHYPRHECISAYDEELA 120
Cdd:cd18405   3 VVINVSGLRFETQLKTLAQFPETLLGDPEkRMRYFDPLRNEYFFDRNRPSFDAILYYYQSgGRLKRPVNVPFDIFSEEVK 82

                ....
gi 9790093  121 FFGL 124
Cdd:cd18405  83 FYEL 86

Shal-type voltage-gated potassium channels, N-terminal; This family represents the short N-terminal helical domain of Shal-type voltage-gated potassium channels. The domain interacts with Kv channel-interacting proteins to modulate cell surface expression and the function of Kv4 channels. The interaction of the N-terminus of Shal-type protein Kv4.2 and the Kv interacting protein KChiP1 forms a structure which is like the structure between calmodulin and its target peptides when they interact. Interactions of an N terminal alpha helix in Kv4.2 and a C terminal alpha helix in KChIP1 are essential for the modulation of Kv4.2 by KChIPs.

                          10        20
                  ....*....|....*....|....*...
gi 9790093      3 AGVAAWLPFARAAAIGWMPVASGPMPAP 30
Cdd:pfam11601   1 ASVAAWLPFARAAAIGWVPVARNPLPPP 28

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel regulatory protein (KCNRG); KCNRG, also called potassium channel regulator or protein CLLD4, is an endoplasmic reticulum (ER)-associated tumor suppressor that regulates Kv1 family potassium channel proteins by retaining a fraction of the channels in endomembranes. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9790093   42 LIVLNVSGTRFQTWQDTLERYPDT----LLGSSERDFfyHPETQQYFFDRDPDIFRHILNFYRTGKLHYPRHecISAYD- 116
Cdd:cd18375   2 LVTLNVGGKKFTTRPSTLRRFPDSrlarMLDGKDQDF--KVVNGQFFVDRDGSLFSYILDYLRTGQLTLPTE--FSDYNr 77

                        90
                ....*....|..
gi 9790093  117 --EELAFFGLIP 126
Cdd:cd18375  78 laREAEFYGLYS 89

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein KCTD11; KCTD11 may function as an antagonist of the Hedgehog pathway of cell proliferation and differentiation by affecting the nuclear transfer of transcription factor GLI1, thus maintaining cerebellar granule cells in the undifferentiated state. It is a probable substrate-specific adapter for a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex towards HDAC1. It contains a BTB/POZ domain; in some cases the domain may be truncated. 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. Variants of the human/mouse KCTD11 appear to contain truncated BTB/POZ domains.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGSSER-----DFFYHPETQ-QYFFDRDPDIFRHILNFYRTGKLHYPR 108
Cdd:cd18370   1 VTLNVGGTLYSTTLETLTRFPDSMLGAMFRagtpiPPNLNMQGGgHYFIDRDGKAFRHILNFLRLGRLDLPR 72

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.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLGSSER-DFFYHPETQ-QYFFDRDPDIFRHILNFYRTGKLHYP 107
Cdd:cd18394   5 VTLNVGGHLYTTSLSTLTRYPDSMLGAMFRgDFPTARDSQgNYFIDRDGPLFRYILNFLRTSELTLP 71

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in SH3KBP1-binding protein 1 (SHKBP1); SHKBP1, also called SETA-binding protein 1, interacts with cathepsin B and participates in tumor necrosis factor (TNF)-induced apoptosis in ovarian cancer cells. It can promote epidermal growth factor receptor (EGFR) signaling by interrupting c-Cbl-CIN85 complex and inhibiting EGFR degradation. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, 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.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9790093   42 LIVLNVSGTRFQTWQDTLERYPDTLLGS--SERDFFYHPETQQYFFDRDPDIFRHILNFYRTGKLHyPRHECISAYDEEL 119
Cdd:cd18393   3 VIHLNVGGKRFSTSRQTLTWIPDSFFSSllSGRISTLKDETGAIFIDRDPTVFAPILNFLRTKELD-PRGIHVSLLLHEA 81

                ....*..
gi 9790093  120 AFFGLIP 126
Cdd:cd18393  82 QFYGITP 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily G member 4 (KCNG4); KCNG4, also called voltage-gated potassium channel subunit Kv6.4, is a silent voltage-gated potassium (KvS) channel subunit that 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. 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. KCNG4 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.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9790093   43 IVLNVSGTRFQTWQDTLERYPDTLLG-----SSERDFF-----YHPETQQYFFDRDPDIFRHILNFYRTGKLHYPRHECI 112
Cdd:cd18423   4 IIINVGGIKYLMPWSTLDEFPLTRLGklkfcSSYEEIVqicddYDEDTNEFFFDRNPCAFRMIVSFLAAGKLRLLREMCA 83

                        90       100
                ....*....|....*....|..
gi 9790093  113 SAYDEELAFFGLIPEIIGDCCY 134
Cdd:cd18423  84 LSFQEELTYWGIEEANLERCCL 105