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 1017029524 219 SKLFSCVSISVVLASIAAMCIHSLPEYQareaaaavaavaagrspegVRDDPVLRRLEYFCIAWFSFEVSSRLLLAPSTR 298
Cdd:pfam00520   1 SRYFELFILLLILLNTIFLALETYFQPE-------------------EPLTTVLEILDYVFTGIFTLEMLLKIIAAGFKK 61

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1017029524 299 NFFCHPLNLIDIVSVLPFYLTLLAGVALGdqggkefghlGKVVQVFRLMRIFRVLKLARHSTGLRSLGATLKHSYREVGI 378
Cdd:pfam00520  62 RYFRSPWNILDFVVVLPSLISLVLSSVGS----------LSGLRVLRLLRLLRLLRLIRRLEGLRTLVNSLIRSLKSLGN 131

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1017029524 379 LLLYLAVGVSVFSGVAY-------TAEKEEDVG---FNTIPACWWWGTVSMTTVGYGDVVPVTVAGKLA-------ASGC 441
Cdd:pfam00520 132 LLLLLLLFLFIFAIIGYqlfggklKTWENPDNGrtnFDNFPNAFLWLFQTMTTEGWGDIMYDTIDGKGEfwayiyfVSFI 211

                         250       260
                  ....*....|....*....|....*..
gi 1017029524 442 ILGGILVVALPITIIFNKFSHFYRRQK 468
Cdd:pfam00520 212 ILGGFLLLNLFIAVIIDNFQELTERTE 238

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 1017029524 219 SKLFSCVSISVVLASIAAMCIHSLPEYQareaaaavaavaagrspegVRDDPVLRRLEYFCIAWFSFEVSSRLLLAPSTR 298
Cdd:pfam00520   1 SRYFELFILLLILLNTIFLALETYFQPE-------------------EPLTTVLEILDYVFTGIFTLEMLLKIIAAGFKK 61

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1017029524 299 NFFCHPLNLIDIVSVLPFYLTLLAGVALGdqggkefghlGKVVQVFRLMRIFRVLKLARHSTGLRSLGATLKHSYREVGI 378
Cdd:pfam00520  62 RYFRSPWNILDFVVVLPSLISLVLSSVGS----------LSGLRVLRLLRLLRLLRLIRRLEGLRTLVNSLIRSLKSLGN 131

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1017029524 379 LLLYLAVGVSVFSGVAY-------TAEKEEDVG---FNTIPACWWWGTVSMTTVGYGDVVPVTVAGKLA-------ASGC 441
Cdd:pfam00520 132 LLLLLLLFLFIFAIIGYqlfggklKTWENPDNGrtnFDNFPNAFLWLFQTMTTEGWGDIMYDTIDGKGEfwayiyfVSFI 211

                         250       260
                  ....*....|....*....|....*..
gi 1017029524 442 ILGGILVVALPITIIFNKFSHFYRRQK 468
Cdd:pfam00520 212 ILGGFLLLNLFIAVIIDNFQELTERTE 238

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 1017029524   54 VNVGGVRRQLSARALARFPGTRLGRLQaaaseeqarrLCDDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDElCVFA 133
Cdd:smart00225   4 LVVGGKKFHAHKAVLAAHSPYFKALFS----------SDFKESDKSEIYLDDVSPEDFRALLNFLYTGKLDLPEE-NVEE 72

                           90       100
                   ....*....|....*....|...
gi 1017029524  134 FGQEADYWGLgENALAACCRARY 156
Cdd:smart00225  73 LLELADYLQI-PGLVELCEEFLL 94

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 1 (KCNS1); KCNS1, also called delayed-rectifier K(+) channel alpha subunit 1 or voltage-gated potassium channel subunit Kv9.1, is a modulatory alpha subunit of voltage-gated potassium channel that mediates neuropathic pain following nerve injury. It can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1) and KCNB2 (also known as Kv2.2), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1 and KCNB2. 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. KCNS1 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 1017029524  52 LRVNVGGVRRQLSARALARFPGTRLGRLQAAASEEQARRLCDDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDELCV 131
Cdd:cd18426     1 ININVGGLKRRLSSSTLSKFPDTRLGRLLSCDSEESILQICDDYDVSAKEFYFDRNPGLFPYVLHFYQTGKLHIMEELCV 80

                          90       100
                  ....*....|....*....|....*
gi 1017029524 132 FAFGQEADYWGLGENALAACCRARY 156
Cdd:cd18426    81 FSFSQEIEYWGINEFFLDSCCSYRY 105

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 1017029524  53 RVNVGGVRRQLSARALARFPGTRLGRLQAAASEEQARRLCDDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDELCVF 132
Cdd:cd18378     5 LLNVGGVRHEVLWRTLDRLPRTRLGRLRECNTHESLLELCDDYDLEDNEYFFDRHPGAFTSILNFYRTGKLHMPEEMCVL 84

                          90       100
                  ....*....|....*....|....
gi 1017029524 133 AFGQEADYWGLGENALAACCRARY 156
Cdd:cd18378    85 SFSQELEYWGIDEIYLESCCQHRY 108

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 1017029524  37 PGPDTGIRWRRSDEALRVNVGGVRRQLSARALARFPGTRLGRLQAAASEEQARRLCDDYDEAAREFYFDRHPGFFLSLLH 116
Cdd:cd18412     4 PEPVEIIRSKACSRRVKINVGGLNHEVLWRTLDRLPRTRLGKLRDCNTHESLLEVCDDYNLNENEYFFDRHPGAFTSILN 83

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 1017029524 117 FYRTGHLHVLDELCVFAFGQEADYWGLGENALAACCRARYLERR 160
Cdd:cd18412    84 FYRTGKLHMMEEMCALSFGQELDYWGIDEIYLESCCQARYHQKK 127

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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1017029524  54 VNVGGVRRQLSARALARFPGTRLGRLQAAASEEQARRLCDDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDELCVFA 133
Cdd:cd18413     6 INVGGVKHEVLWRTLDRMPHTRLGKLRDSNTHEAIVELCDDYSLADNEYFFDRHPRSFASILNFYRTGKLHLVEEMCVLA 85

                          90       100
                  ....*....|....*....|...
gi 1017029524 134 FGQEADYWGLGENALAACCRARY 156
Cdd:cd18413    86 FSDDLEYWGVDELYLESCCQHKY 108

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 1017029524  43 IRWRRSDEALRVNVGGVRRQLSARALARFPGTRLGRLQAAASEEQARRLCDDYDEAAREFYFDRHPGFFLSLLHFYRTGH 122
Cdd:cd18411     3 IRSKACSRRVKLNVGGLAHEVLWRTLDRLPRTRLGKLRDCNTHESLMEICDDYNLEENEYFFDRHPGAFTSILNFYRTGK 82

                          90       100       110
                  ....*....|....*....|....*....|....
gi 1017029524 123 LHVLDELCVFAFGQEADYWGLGENALAACCRARY 156
Cdd:cd18411    83 LHMMEEMCALSFSQELDYWGIDEIYLESCCQARY 116

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 1017029524  54 VNVGGVRRQLSARALARFPGTRLGRLQAAASEEQARRLCDDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDELCVFA 133
Cdd:cd18382     3 INVGGARYSLPWSTLDRFPLTRLSRLKACRSEDDILRVCDDYDVERNEFFFDRSPEAFGVILLFLRAGKLRLLREMCALS 82

                          90       100
                  ....*....|....*....|....*.
gi 1017029524 134 FGQEADYWGLGENALAACCRARYLER 159
Cdd:cd18382    83 FQEELAYWGIEEAHLERCCKRRLLRR 108

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 1017029524  52 LRVNVGGVRRQLSARALARFPGTRLGRLqaaaSEEQARRLcdDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDELCV 131
Cdd:cd18379     1 IVINVGGVRHETYKSTLRNLPDTRLAWL----TETEASAF--DYDPVTGEFFFDRHPGVFAQILNYYRTGKLHCPADVCG 74

                          90       100       110
                  ....*....|....*....|....*....|..
gi 1017029524 132 FAFGQEADYWGLGENALAACCRARYLERRLTQ 163
Cdd:cd18379    75 PLFEEELAFWGIDETQIEPCCWMTYRQHRDAQ 106

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 1017029524  54 VNVGGVRRQLSARALARFPGTRLGRL--QAAASEEQARRLCDDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDELCV 131
Cdd:cd18381     5 VNVGGVRQVLYGDVLNRYPETRLAELlnCLSGGYDAIFSLCDDYDPGKREFYFDRDPDAFKCIIEVYYYGEIHMKKGICP 84

                          90       100       110
                  ....*....|....*....|....*....|
gi 1017029524 132 FAFGQEADYWGLGENALAACCRARYLERRL 161
Cdd:cd18381    85 ICFKNEMDFWRVDLDFLDECCKCHLSEKRE 114

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 1017029524  49 DEALRVNVGGVRRQLSARALARFPGTRLGRLQAAASeeqarrlcdDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDE 128
Cdd:cd18416     1 ENRVVLNVGGIRHETYKATLKKIPATRLSRLTEALA---------NYDPVLNEYFFDRHPGVFAQILNYYRTGKLHYPTD 71

                          90       100       110
                  ....*....|....*....|....*....|....*
gi 1017029524 129 LCVFAFGQEADYWGLGENALAACCRARYLERRLTQ 163
Cdd:cd18416    72 VCGPLFEEELEFWGLDANQVEPCCWMTYTAHRDTQ 106

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 1017029524  50 EALRVNVGGVRRQLSARALARFPGTRLGRLqaaASEEQARRLcdDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDEL 129
Cdd:cd18414     3 DRIVINVGGTRHETYRSTLRTLPGTRLAWL---AEPDAHSNF--DYDPRADEFFFDRHPGVFAHILNYYRTGKLHCPADV 77

                          90       100       110
                  ....*....|....*....|....*....|.
gi 1017029524 130 CVFAFGQEADYWGLGENALAACCRARYLERR 160
Cdd:cd18414    78 CGPLYEEELAFWGIDETDVEPCCWMTYRQHR 108

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 1017029524  39 PDTGIRWRRSDEALRVNVGGVRRQLSARALARFPGTRLGrlqaaASEEQARrlcddYDEAAREFYFDRHPGFFLSLLHFY 118
Cdd:cd18417    24 KPPSDKKRRNDEILVVNVSGRRFQTWKNTLDRYPDTLLG-----SSEKEFF-----YNEDTQEYFFDRDPEMFRHILNFY 93

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|..
gi 1017029524 119 RTGHLHVLDELCVFAFGQEADYWGLGENALAACCRARYLERR 160
Cdd:cd18417    94 RTGRLHYPRHECIQAFDEELSFYGIIPEIIGDCCLEEYRDRK 135

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 1017029524  46 RRSDEALRVNVGGVRRQLSARALARFPGTRLGRlqaaaSEEQARrlcddYDEAAREFYFDRHPGFFLSLLHFYRTGHLHV 125
Cdd:cd18419    31 KRQDELIVLNVSGRRFQTWRTTLERYPDTLLGS-----TEKEFF-----FNEDTKEYFFDRDPEVFRCVLNFYRTGKLHY 100

                          90       100       110
                  ....*....|....*....|....*....|....*
gi 1017029524 126 LDELCVFAFGQEADYWGLGENALAACCRARYLERR 160
Cdd:cd18419   101 PRYECISAYDEELAFYGILPEIIGDCCYEEYKDRK 135

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 1017029524  37 PGPDTGIRWRRSDEALRVNVGGVRRQLSARALARFPGTRLGrlqaaaSEEQARRlcddYDEAAREFYFDRHPGFFLSLLH 116
Cdd:cd18420    23 PPPVDQERRRTDDEKLIINVSGRRFETWRNTLEKYPDTLLG------SNEREFF----YDEETKEYFFDRDPDIFRHILN 92

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 1017029524 117 FYRTGHLHVLDELCVFAFGQEADYWGLGENALAACCRARYLERR 160
Cdd:cd18420    93 YYRTGKLHYPKHECLTAYDEELAFFGIMPDIIGDCCYEDYRDRK 136

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 1017029524  50 EALRVNVGGVRRQLSARALARFPGTRLGrlqaaaseeQARRLCDDYDEAAREFYFDRHPGFFLSLLHFYRT-GHLHVLDE 128
Cdd:cd18408     6 ERVVLNVAGLRFETRARTLGRFPDTLLG---------DPARRGRFYDDRRREYFFDRHRPSFDAVLYYYQSgGRLRRPAH 76

                          90       100
                  ....*....|....*....|.
gi 1017029524 129 LCVFAFGQEADYWGLGENALA 149
Cdd:cd18408    77 VPLDVFLEEVAFYGLGAAALA 97

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 1017029524   54 VNVGGVRRQLSARALARFPGTRLGRLQaaaseeqarrLCDDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDElCVFA 133
Cdd:smart00225   4 LVVGGKKFHAHKAVLAAHSPYFKALFS----------SDFKESDKSEIYLDDVSPEDFRALLNFLYTGKLDLPEE-NVEE 72

                           90       100
                   ....*....|....*....|...
gi 1017029524  134 FGQEADYWGLgENALAACCRARY 156
Cdd:smart00225  73 LLELADYLQI-PGLVELCEEFLL 94

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 1017029524  50 EALRVNVGGVRRQLSARALARFPGTRLGrlqaaaseEQARRLcDDYDEAAREFYFDRHPGFFLSLLHFYRT-GHLHVLDE 128
Cdd:cd18410     1 ERVVINVSGLRFETQLKTLNQFPDTLLG--------DPQRRN-RYYDPLRNEYFFDRNRPSFDAILYYYQSgGRLRRPVN 71

                          90       100
                  ....*....|....*....|
gi 1017029524 129 LCVFAFGQEADYWGLGENAL 148
Cdd:cd18410    72 VPLDVFSEEIKFYELGENAF 91

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 1017029524  52 LRVNVGGVRRQLSARALARFPGTRLGRLqaaasEEQARRLCDDYDEAareFYFDRHPGFFLSLLHFYRTGHLHV------ 125
Cdd:cd18316     1 VKLNVGGTLFTTSRSTLLKDPDSLLAAL-----FSGRWPLPRDEDGS---IFIDRDPELFRHILNFLRTGKLPLpsdfve 72

                          90
                  ....*....|....*.
gi 1017029524 126 LDELCvfafgQEADYW 141
Cdd:cd18316    73 LEELL-----AEAEFY 83

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 1017029524  50 EALRVNVGGVRRQLSARALARFPGTRLGrlqaaaseeQARRLCDDYDEAAREFYFDRHPGFFLSLLHFYRT-GHLHVLDE 128
Cdd:cd18403     1 ERVVINISGLRFETQLKTLAQFPETLLG---------DPKKRMRYFDPLRNEYFFDRNRPSFDAILYYYQSgGRLRRPVN 71

                          90       100
                  ....*....|....*....|
gi 1017029524 129 LCVFAFGQEADYWGLGENAL 148
Cdd:cd18403    72 VPLDIFSEEIRFYELGEEAM 91

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 1017029524  50 EALRVNVGGVRRQLSARALARFPGTRLGrlqaaaseeQARRLCDDYDEAAREFYFDRHPGFFLSLLHFYRT-GHLHVLDE 128
Cdd:cd18402     9 ERVVINIAGLRFETQLKTLAQFPNTLLG---------NPKKRMRYFDPLRNEYFFDRNRPSFDAILYYYQSgGRLRRPVN 79

                          90
                  ....*....|....*....
gi 1017029524 129 LCVFAFGQEADYWGLGENA 147
Cdd:cd18402    80 VPLDMFSEEIKFYELGEEA 98

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 1017029524  50 EALRVNVGGVRRQLSARALARFPGTRLGRLQAAASEeqarrlcdDYDEAAREFYFDRHPGFFLSLLHFYRTGHLHVLDEL 129
Cdd:cd18375     1 ELVTLNVGGKKFTTRPSTLRRFPDSRLARMLDGKDQ--------DFKVVNGQFFVDRDGSLFSYILDYLRTGQLTLPTEF 72

                          90
                  ....*....|....*
gi 1017029524 130 CVF-AFGQEADYWGL 143
Cdd:cd18375    73 SDYnRLAREAEFYGL 87

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 1017029524  50 EALRVNVGGVRRQLSARALARFPGTRLGrlqaaaseEQARRLcDDYDEAAREFYFDRHPGFFLSLLHFYRT-GHLHVLDE 128
Cdd:cd18406     1 ERVIINIAGLRFETQLGTLNQFPDTLLG--------DPDKRM-RYFDPLRNEYFFDRNRPSFDGILYFYQSgGKIRRPVN 71

                          90       100
                  ....*....|....*....|
gi 1017029524 129 LCVFAFGQEADYWGLGENAL 148
Cdd:cd18406    72 VSIDVFADEIRFYQLGEEAM 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 10 (KCNA10); KCNA10, also called voltage-gated potassium channel subunit Kv1.8, is a cyclic nucleotide-gated, voltage-activated 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. KCNA10 is expressed in proximal tubular cells, glomerular and vascular endothelial cells, as well as in vascular smooth muscle cells. It may facilitate proximal tubular sodium absorption by stabilizing cell membrane voltage. The channel activity is up-regulated by cAMP. 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. KCNA10 is an alpha subunit that forms functional homotetrameric channels 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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1017029524  54 VNVGGVRRQLSARALARFPGTRLGrlqaaaseEQARRLcDDYDEAAREFYFDRHPGFFLSLLHFYRTG 121
Cdd:cd18409     5 INIAGLRFETQLKTLDQFPDTLLG--------DPEKRM-KYFDSMRNEYFFDRNRPSFDGILYYYQSG 63