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 2329048185 197 ARVVAIISVFVILLSIVIFCLETLPEFKHYkvfntttngtkieedevpdITDPFFLIETLCIIWFTFELTVRFLACPNKL 276
Cdd:pfam00520   1 SRYFELFILLLILLNTIFLALETYFQPEEP-------------------LTTVLEILDYVFTGIFTLEMLLKIIAAGFKK 61

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2329048185 277 NFCRDVMNVIDIIAIIPYFITLAtvvaeeedtlnlpkapvspqdksSNQAMSLAILRVIRLVRVFRIFKLSRHSKGLQIL 356
Cdd:pfam00520  62 RYFRSPWNILDFVVVLPSLISLV-----------------------LSSVGSLSGLRVLRLLRLLRLLRLIRRLEGLRTL 118

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2329048185 357 GRTLKASMRELGLLIFFLFIGVVLFSSAVYFAEAGSENSF---------FKSIPDAFWWAVVTMTTVGYGDMTPVGVWGK 427
Cdd:pfam00520 119 VNSLIRSLKSLGNLLLLLLLFLFIFAIIGYQLFGGKLKTWenpdngrtnFDNFPNAFLWLFQTMTTEGWGDIMYDTIDGK 198

                         250       260       270
                  ....*....|....*....|....*....|....*....
gi 2329048185 428 -------IVGSLCAIAGVLTIALPVPVIVSNFNYFYHRE 459
Cdd:pfam00520 199 gefwayiYFVSFIILGGFLLLNLFIAVIIDNFQELTERT 237

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 2329048185 197 ARVVAIISVFVILLSIVIFCLETLPEFKHYkvfntttngtkieedevpdITDPFFLIETLCIIWFTFELTVRFLACPNKL 276
Cdd:pfam00520   1 SRYFELFILLLILLNTIFLALETYFQPEEP-------------------LTTVLEILDYVFTGIFTLEMLLKIIAAGFKK 61

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2329048185 277 NFCRDVMNVIDIIAIIPYFITLAtvvaeeedtlnlpkapvspqdksSNQAMSLAILRVIRLVRVFRIFKLSRHSKGLQIL 356
Cdd:pfam00520  62 RYFRSPWNILDFVVVLPSLISLV-----------------------LSSVGSLSGLRVLRLLRLLRLLRLIRRLEGLRTL 118

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2329048185 357 GRTLKASMRELGLLIFFLFIGVVLFSSAVYFAEAGSENSF---------FKSIPDAFWWAVVTMTTVGYGDMTPVGVWGK 427
Cdd:pfam00520 119 VNSLIRSLKSLGNLLLLLLLFLFIFAIIGYQLFGGKLKTWenpdngrtnFDNFPNAFLWLFQTMTTEGWGDIMYDTIDGK 198

                         250       260       270
                  ....*....|....*....|....*....|....*....
gi 2329048185 428 -------IVGSLCAIAGVLTIALPVPVIVSNFNYFYHRE 459
Cdd:pfam00520 199 gefwayiYFVSFIILGGFLLLNLFIAVIIDNFQELTERT 237

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 2329048185   70 VVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYfDPLRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNvPLDVFSEEIK 149
Cdd:smart00225   2 VTLVVGGKKFHAHKAVLAAHSPYFKALFSSDFKE-SDKSEIYLDDVSPEDFRALLNFLYT-GKLDLPEE-NVEELLELAD 78

                   ....
gi 2329048185  150 FYEL 153
Cdd:smart00225  79 YLQI 82

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 2329048185  68 ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSEE 147
Cdd:cd18410     1 ERVVINVSGLRFETQLKTLNQFPDTLLGDPQRRNRYYDPLRNEYFFDRNRPSFDAILYYYQSGGRLRRPVNVPLDVFSEE 80

                          90       100
                  ....*....|....*....|
gi 2329048185 148 IKFYELGDQAINKFREDEGF 167
Cdd:cd18410    81 IKFYELGENAFEKYREDEGF 100

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 2329048185  68 ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSEE 147
Cdd:cd18377     1 ERVVINVSGLRFETQLKTLAQFPNTLLGDPNKRMRFFDPLRNEYFFDRNRPSFDAILYYYQSGGRLRRPVNVPLDIFLEE 80

                  ....*
gi 2329048185 148 IKFYE 152
Cdd:cd18377    81 IRFYE 85

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 2329048185  67 CERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSE 146
Cdd:cd18408     5 CERVVLNVAGLRFETRARTLGRFPDTLLGDPARRGRFYDDRRREYFFDRHRPSFDAVLYYYQSGGRLRRPAHVPLDVFLE 84

                          90       100       110
                  ....*....|....*....|....*....|
gi 2329048185 147 EIKFYELGDQAINKFREDEGFIKEEERPLP 176
Cdd:cd18408    85 EVAFYGLGAAALARLREDEGCPVPPERPLP 114

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 2329048185  62 HDHDFCERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPL 141
Cdd:cd18402     3 DDHECCERVVINIAGLRFETQLKTLAQFPNTLLGNPKKRMRYFDPLRNEYFFDRNRPSFDAILYYYQSGGRLRRPVNVPL 82

                          90
                  ....*....|....*.
gi 2329048185 142 DVFSEEIKFYELGDQA 157
Cdd:cd18402    83 DMFSEEIKFYELGEEA 98

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 2329048185 197 ARVVAIISVFVILLSIVIFCLETLPEFKHYkvfntttngtkieedevpdITDPFFLIETLCIIWFTFELTVRFLACPNKL 276
Cdd:pfam00520   1 SRYFELFILLLILLNTIFLALETYFQPEEP-------------------LTTVLEILDYVFTGIFTLEMLLKIIAAGFKK 61

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2329048185 277 NFCRDVMNVIDIIAIIPYFITLAtvvaeeedtlnlpkapvspqdksSNQAMSLAILRVIRLVRVFRIFKLSRHSKGLQIL 356
Cdd:pfam00520  62 RYFRSPWNILDFVVVLPSLISLV-----------------------LSSVGSLSGLRVLRLLRLLRLLRLIRRLEGLRTL 118

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2329048185 357 GRTLKASMRELGLLIFFLFIGVVLFSSAVYFAEAGSENSF---------FKSIPDAFWWAVVTMTTVGYGDMTPVGVWGK 427
Cdd:pfam00520 119 VNSLIRSLKSLGNLLLLLLLFLFIFAIIGYQLFGGKLKTWenpdngrtnFDNFPNAFLWLFQTMTTEGWGDIMYDTIDGK 198

                         250       260       270
                  ....*....|....*....|....*....|....*....
gi 2329048185 428 -------IVGSLCAIAGVLTIALPVPVIVSNFNYFYHRE 459
Cdd:pfam00520 199 gefwayiYFVSFIILGGFLLLNLFIAVIIDNFQELTERT 237

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 2329048185  70 VVINVSGLRFETQLRTLNQFPDTLLGDPARRLR--YFDPLRNEYFFDRSRPSFDAILYYYQSGGRLrRPVNVPLDVFSEE 147
Cdd:cd18187     1 VVLNVSGTRFVTNRQTLTRHPDTLLGRMFKPGRefTFPNETGEYFIDRDPTVFRTILNYYRTGKLN-CPDGISIPDLREE 79

                  ....
gi 2329048185 148 IKFY 151
Cdd:cd18187    80 CDFY 83

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 2329048185  69 RVVINVSGLRFETQLRTLNQFPDTLLGDpARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNVPLDVFSEEI 148
Cdd:cd18380     1 RIVINVSGRRFETWKNTLEKYPDTLLGS-TEKEFFYDDDTKEYFFDRDPEIFRHILNFYRT-GKLHYPRHECISAYDDEL 78

                          90
                  ....*....|
gi 2329048185 149 KFYELGDQAI 158
Cdd:cd18380    79 AFFGILPEII 88

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 2329048185  68 ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLrYFDPLRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNVPLDVFSEE 147
Cdd:cd18417    35 EILVVNVSGRRFQTWKNTLDRYPDTLLGSSEKEF-FYNEDTQEYFFDRDPEMFRHILNFYRT-GRLHYPRHECIQAFDEE 112

                          90       100
                  ....*....|....*....|.
gi 2329048185 148 IKFYEL-----GDQAINKFRE 163
Cdd:cd18417   113 LSFYGIipeiiGDCCLEEYRD 133

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shal and similar proteins; Drosophila melanogaster Shal, also called Shaker cognate l or Shal2, is a transient potassium current (I(A)) channel, which is required for maintaining excitability during repetitive firing and normal locomotion in Drosophila. It may play a role in the nervous system and in the regulation of beating frequency in pacemaker cells. Shal mediates the voltage-dependent potassium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a 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. Shal 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 2329048185  59 PIPHDHDFC--ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLrYFDPLRNEYFFDRSRPSFDAILYYYQSgGRLRRP 136
Cdd:cd18420    25 PVDQERRRTddEKLIINVSGRRFETWRNTLEKYPDTLLGSNEREF-FYDEETKEYFFDRDPDIFRHILNYYRT-GKLHYP 102

                          90
                  ....*....|....*
gi 2329048185 137 VNVPLDVFSEEIKFY 151
Cdd:cd18420   103 KHECLTAYDEELAFF 117

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 2329048185  70 VVINVSGLRFETQLRTLNQFPDTLLGDPARRLrYFDPLRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNVPLDVFSEEIK 149
Cdd:cd18418     2 IVLNVSGTRFQTWRNTLERYPDTLLGSSERDF-FYHEETQEYFFDRDPDIFRHILNFYRT-GKLHYPRHECISAYDEELA 79

                  ..
gi 2329048185 150 FY 151
Cdd:cd18418    80 FF 81

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNB/Kv2 subfamily of Shab-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 two alpha subunit members, Kv2.1 (KCNB1) and Kv2.2 (KCNB2), which are orthologs of the Shab gene in Drosophila. They are delayed-rectifier potassium currents in various neurons, although their physiological roles often remain elusive. Kv2/KCNB 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 2329048185  69 RVVINVSGLRFETQLRTLNQFPDTLLGdparRLRY-------------FDPLRNEYFFDRSRPSFDAILYYYQSgGRLRR 135
Cdd:cd18378     3 RVLLNVGGVRHEVLWRTLDRLPRTRLG----RLREcnthesllelcddYDLEDNEYFFDRHPGAFTSILNFYRT-GKLHM 77

                          90
                  ....*....|....*.
gi 2329048185 136 PVNVPLDVFSEEIKFY 151
Cdd:cd18378    78 PEEMCVLSFSQELEYW 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shab and similar proteins; Shab is a slow delayed rectifier 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. Shab 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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2329048185  69 RVVINVSGLRFETQLRTLNQFPDTLLGdparRLRY-------------FDPLRNEYFFDRSRPSFDAILYYYQSG 130
Cdd:cd18413     3 RVVINVGGVKHEVLWRTLDRMPHTRLG----KLRDsntheaivelcddYSLADNEYFFDRHPRSFASILNFYRTG 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 2329048185  70 VVINVSGLRFETQLRTLNQFPDTLLGDPAR-RLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSEEI 148
Cdd:cd18316     1 VKLNVGGTLFTTSRSTLLKDPDSLLAALFSgRWPLPRDEDGSIFIDRDPELFRHILNFLRTGKLPLPSDFVELEELLAEA 80

                  ...
gi 2329048185 149 KFY 151
Cdd:cd18316    81 EFY 83

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 2329048185  68 ERVVINVSGLRFETQLRTLNQFPDTLL---------GDPA----RRLRYFDPLR--NEYFFDRSRPSFDAILYYYQSgGR 132
Cdd:cd18415     2 ERIILNVGGTRHETYRSTLKTLPGTRLallassdpqGDCLtqcsQVGGSDGSPGggNEFFFDRHPGVFAYVLNYYRT-GK 80

                          90
                  ....*....|....*....
gi 2329048185 133 LRRPVNVPLDVFSEEIKFY 151
Cdd:cd18415    81 LHCPADVCGPLFEEELAFW 99

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2329048185  70 VVINVSGLRFETQLRTLNQFPDTLLG---------DPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQsGGRLR 134
Cdd:cd18382     1 VIINVGGARYSLPWSTLDRFPLTRLSrlkacrsedDILRVCDDYDVERNEFFFDRSPEAFGVILLFLR-AGKLR 73

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily B member 1 (KCNB1); KCNB1, also called delayed rectifier potassium channel 1 (DRK1) or voltage-gated potassium channel subunit Kv2.1, mediates transmembrane potassium transport in excitable membranes, primarily in the brain, but also in the pancreas and cardiovascular system. 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. KCNB1 is involved in the regulation of the action potential (AP) repolarization, duration and frequency of repetitive AP firing in neurons, muscle cells and endocrine cells and plays a role in homeostatic attenuation of electrical excitability throughout 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. KCNB1 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 2329048185  69 RVVINVSGLRFETQLRTLNQFPDTLLGDpARRLRYFDPL----------RNEYFFDRSRPSFDAILYYYQSgGRLRRPVN 138
Cdd:cd18411    11 RVKLNVGGLAHEVLWRTLDRLPRTRLGK-LRDCNTHESLmeicddynleENEYFFDRHPGAFTSILNFYRT-GKLHMMEE 88

                          90
                  ....*....|...
gi 2329048185 139 VPLDVFSEEIKFY 151
Cdd:cd18411    89 MCALSFSQELDYW 101

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily G members, KCNG1 and KCNG2; KCNG1, also called voltage-gated potassium channel subunit Kv6.1 or kH2, functions as a regulatory alpha-subunit of voltage-gated potassium channel 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. KCNG2, also called cardiac potassium channel subunit or voltage-gated potassium channel subunit Kv6.2, is a new gamma-subunit of voltage-gated potassium channels that 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. 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. KCNG1 and KCNG2 are regulatory alpha subunits and do not form homomultimers. They form heteromultimers (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 2329048185  65 DFCERVVINVSGLRFETQLRTLNQFPDTLLGdparRLRY-------------FDPLRNEYFFDRSRPSFDAILYYYQSgG 131
Cdd:cd18421     1 DRTRHVIINVGGIKYRIPWTTLEEFPLTRLG----QLKScnnfdeimdicddYDVTCNEFFFDRNPCAFRTILTFLRA-G 75

                  ...
gi 2329048185 132 RLR 134
Cdd:cd18421    76 KLR 78

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily V member 2 (KCNV2); KCNV2, also called voltage-gated potassium channel subunit Kv8.2, is a modulatory voltage-gated potassium channel alpha subunit that modulates channel activity by shifting the threshold and the half-maximal activation to more negative values. KCNV2 is essential for visual function and cone survival. 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. KCNV2 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 2329048185  72 INVSGLRFETQLRTLNQFPDTLLG------DPARRLRYFD---PLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLD 142
Cdd:cd18425     3 INVGGTSYQISYRVAASYPKTRIGrlatytDRSRKLDLCDdynVQNDEYFFDRDPAVFHHIYNFYRTGVLWVKDELCPRN 82

                  ....*....
gi 2329048185 143 vFSEEIKFY 151
Cdd:cd18425    83 -FLEEINYW 90

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2329048185  69 RVVINVSGLRFETQLRTLNQFPDTLLGDpARRLRYFDPL----------RNEYFFDRSRPSFDAILYYYQSG 130
Cdd:cd18412    18 RVKINVGGLNHEVLWRTLDRLPRTRLGK-LRDCNTHESLlevcddynlnENEYFFDRHPGAFTSILNFYRTG 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD1 and KCTD15; This subfamily of KCTD proteins includes KCTD1 and KCTD15. KCTD1 is a nuclear BTB/POZ domain-containing protein that acts as a transcriptional repressor and mediates protein-protein interactions through a BTB domain. It represses the transcriptional activity of AP-2 family members, including TFAP2A, TFAP2B and TFAP2C. It also functions as a novel inhibitor of the Wnt signaling pathway. Mutations in KCTD1 cause scalp-ear-nipple (SEN) syndrome. KCTD15 is a BTB/POZ domain-containing protein that plays a role in the regulation of neural crest (NC) formation and other steps in embryonic development. It inhibits AP2 transcriptional activity by interaction with its activation domain. 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. The KCTD1 BTB domains form pentamers.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2329048185  70 VVINVSGLRFETQLRTLNQFPDTLLGdparrlRYF--------DPLRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNVP- 140
Cdd:cd18361     1 VHIDVGGHIYTSSLETLTKYPESRLG------KLFngsipivlDSLKQHYFIDRDGKMFRHILNFLRT-SKLLLPDDFTe 73

                          90
                  ....*....|...
gi 2329048185 141 LDVFSEEIKFYEL 153
Cdd:cd18361    74 FDLLYEEARYYEL 86

voltage-gated potassium channel protein;

                          10        20
                  ....*....|....*....|....
gi 2329048185 399 SIPDAFWWAVVTMTTVGYGDMTPV 422
Cdd:PRK10537  168 SLSTAFYFSIVTMSTVGYGDIVPV 191

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2329048185  70 VVINVSGLRFETQLRTLNQFPDTLLGDPARRLRY-----------FDPLRNEYFFDRSRPSFDAIL--YYY 127
Cdd:cd18381     3 IVVNVGGVRQVLYGDVLNRYPETRLAELLNCLSGgydaifslcddYDPGKREFYFDRDPDAFKCIIevYYY 73

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD6, KCTD21 and similar proteins; KCTD6, also called KCASH3 (KCTD containing, Cullin3 adaptor, suppressor of Hedgehog 3), is a substrate-specific adaptor of cullin-3, effectively regulating protein levels of the muscle small ankyrin-1 isoform 5 (sAnk1.5). KCTD21, also called KCASH2, functions as a substrate-specific adaptor of cullin-3, promoting the ubiquitination and degradation of histone deacetylase HDAC1, thereby inhibiting the deacetylation-mediated transcriptional activation of the Hedgehog effectors Gli1 and Gli2. 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        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2329048185  70 VVINVSGLRFETQLRTLNQFPDTLLGD------PARRlryfDPlRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNVP-LD 142
Cdd:cd18365     3 VNLNVGGVHYTTTLATLTRFPDSMLGAmfsgsmPTTR----DD-QGNYFIDRDGTLFRYILNFLRS-SQLSLPEDFKeYD 76

                          90
                  ....*....|.
gi 2329048185 143 VFSEEIKFYEL 153
Cdd:cd18365    77 LLLREADFYQI 87

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 2329048185  70 VVINVSGLRFETQLRTLNQFPDTLL-----GDparrlryFDPLRNE---YFFDRSRPSFDAILYYYQSGGRLRRPVNVP- 140
Cdd:cd18376     1 VKLNVGGQKFTTTLDTLTKDPDSMLaamfsGR-------HSLKKDEdgsYFIDRDGTHFRHILNYLRDGEVKIPTEDRSv 73

                          90
                  ....*....|...
gi 2329048185 141 LDVFSEEIKFYEL 153
Cdd:cd18376    74 LKELLEEAEYYQL 86