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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 568986284   1 MLAHMFKDKGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLEEARFFGIDSLIEHLEVAI 74
Cdd:cd18368   27 MLARMFSDDSTWPSSRDENGAYLIDRSPEYFEPILNYLRHGQLILNDGLNPLGVLEEAKFFGIQSLIEILEQLI 100

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 9 (KCTD9); KCTD9 is a BTB/POZ domain-containing protein that contributes to liver injury through NK cell activation during hepatitis B virus-induced acute-on-chronic liver failure. It functions as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex, which mediates the ubiquitination of target proteins, leading to their degradation by the proteasome. 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 KCTD9 BTB domain forms a pentameric structure.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 568986284   1 MLAHMFKDKGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLEEARFFGIDSLIEHLEVAI 74
Cdd:cd18368   27 MLARMFSDDSTWPSSRDENGAYLIDRSPEYFEPILNYLRHGQLILNDGLNPLGVLEEAKFFGIQSLIEILEQLI 100

type III secretion system effector PipB2;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568986284 108 GLNFSGADLSRLDLRYINFKMANLSRCNLAHANLCCANLERADLSGSVLDCANLQGVKMLCSNAEGASLRLCNFEDPSGL 187
Cdd:PRK15196 176 GANLEGAVLFMADCEGANFKGANLSGTSLGDSNFKNACLEDSIMCGATLDHANLTGANLQHASLLGCSMIECNCSGANMD 255

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 568986284 188 KANLEGANLKGVDMEGSQMTGINLRVATLKNAKLKNCNLRGATLAGTDLEncdlsGCDLQEANLRGSNVKGAIFEEMLT 266
Cdd:PRK15196 256 HTNLSGATLIRADMSGATLQGATIMAAIMEGAVLTRANLRKASFISTNLD-----GADLAEANLNNTCFKDCTLTHLRT 329

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
                   ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 568986284    17 DHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGiNLLGVLEEARFFGIDSLIEHLEVAIKNS 77
Cdd:smart00225  37 DKSEIYLDDVSPEDFRALLNFLYTGKLDLPEE-NVEELLELADYLQIPGLVELCEEFLLKL 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 9 (KCTD9); KCTD9 is a BTB/POZ domain-containing protein that contributes to liver injury through NK cell activation during hepatitis B virus-induced acute-on-chronic liver failure. It functions as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex, which mediates the ubiquitination of target proteins, leading to their degradation by the proteasome. 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 KCTD9 BTB domain forms a pentameric structure.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 568986284   1 MLAHMFKDKGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLEEARFFGIDSLIEHLEVAI 74
Cdd:cd18368   27 MLARMFSDDSTWPSSRDENGAYLIDRSPEYFEPILNYLRHGQLILNDGLNPLGVLEEAKFFGIQSLIEILEQLI 100

Uncharacterized conserved protein YjbI, contains pentapeptide repeats [Function unknown];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568986284 111 FSGADLSRLDLRYINFKMANLSRCNLAHANLCCANLERADLSGSVLDCANLQGVKMLcsNAEGASLRLCNFEDPSGLKAN 190
Cdd:COG1357   31 LSGANLSGANLSGANLTGANLSGADLSGADLSGANLSGADLSGANLTGADLSGANLA--NLSGANLSGANLSGANLRGAN 108

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 568986284 191 LEGANLKGVDMEGsqmtginlrvATLKNAKLKNCNLRGATLAGTDLENCDLSGCDLQEANLRGSNVKGAIF 261
Cdd:COG1357  109 LSGANLSGADLSG----------ADLSGANLSGADLSGANLSGANLSGADLSGADLSGANLSGANLSGANL 169

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, and similar proteins; This subfamily includes potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, all of which function as adaptors of Cullin3 based ubiquitin E3 ubiquitin ligases. KCTD2 suppresses gliomagenesis by destabilizing c-Myc. KCTD5 is a negative regulator of the AKT pathway, a key signaling cascade frequently deregulated in cancer. KCTD5 does not impact the operation of Kv4.2, Kv3.4, Kv2.1, or Kv1.2 channels. KCTD17 polyubiquitylates trichoplein, a protein involved in ciliogenesis down-regulation. It is a positive regulator of ciliogenesis, playing a crucial role in the initial steps of axoneme extension. A missense mutation in KCTD17 causes autosomal dominant myoclonus-dystonia (M-D). 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. KCTD5 and KCTD17 BTB domains form pentamer structures.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 568986284  16 QDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLEEARFF 61
Cdd:cd18362   40 KDETGAYLIDRDPTYFGPILNYLRHGKLIIDKDLAEEGVLEEAEFY 85

type III secretion system effector PipB2;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568986284 106 CQGLNFSGADLSRLDLRYINFKMANLSR-----CNLAHANLCCANLERADLSG-SVLDCaNLQGVKMLCSNAEGASLRLC 179
Cdd:PRK15196 189 CEGANFKGANLSGTSLGDSNFKNACLEDsimcgATLDHANLTGANLQHASLLGcSMIEC-NCSGANMDHTNLSGATLIRA 267

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 568986284 180 NFEDpsglkANLEGANLKGVDMEGSQMTGINLRVATLKNAKLKNCNLRGATLAGTDLENCDLSGCDLQEANLRGS 254
Cdd:PRK15196 268 DMSG-----ATLQGATIMAAIMEGAVLTRANLRKASFISTNLDGADLAEANLNNTCFKDCTLTHLRTEDATMSTS 337

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 5 (KCTD5); KCTD5 is a BTB/POZ domain-containing protein that functions as a substrate adaptor for cullin3 based ubiquitin E3 ligases. It is a negative regulator of the AKT pathway, a key signaling cascade frequently deregulated in cancer. KCTD5 does not impact the operation of Kv4.2, Kv3.4, Kv2.1, or Kv1.2 channels. 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. KCTD5 forms pentamers mediated by its BTB domain.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 568986284  16 QDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLEEARFFGIDSLIEHLEVAIK 75
Cdd:cd18390   45 KDETGAYLIDRDPTYFGPVLNYLRHGKLVINKDLAEEGVLEEAEFYNITSLIKLVKDKIR 104

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 568986284   1 MLAHMFKdkGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQL-IVNDGINLLGVLEEARFF 61
Cdd:cd18316   24 LLAALFS--GRWPLPRDEDGSIFIDRDPELFRHILNFLRTGKLpLPSDFVELEELLAEAEFY 83

type III secretion system effector PipB;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568986284 110 NFSGADLSRLDLRYINFKMANLSRCNLAHANLCCANLERADLSGSVLDCANLQGVKMLCSNAEGaslrlcnfedpsglkA 189
Cdd:PRK15197 165 DFQGEDLSDIDASNADFRETTLSNVNLVGANLCCANLHAVNLMGSNMTKANLTHADLTCANMSG---------------V 229

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|.
gi 568986284 190 NLEGANLKGVDMEGSQMTGINLRVATLKNAK-LKNCNLRGA 229
Cdd:PRK15197 230 NLTAAILFGSDLTDTKLNGAKLDKIALTLAKaLTGADLTGS 270

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 568986284    1 MLAHMFKDKGvwGNKQDHRGAFLIDRSPEYFEPILNYLRH-GQLIVNDGINLLGVLEEARFFGIDSLI 67
Cdd:pfam02214  24 RLGRLLELEC--DDYDDDTNEYFFDRSPKHFETILNFYRTgGKLHRPEEVCLDEFLEEAEFYGLDELA 89

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 568986284   1 MLAHMFKdKGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLEEARFF 61
Cdd:cd18187   24 LLGRMFK-PGREFTFPNETGEYFIDRDPTVFRTILNYYRTGKLNCPDGISIPDLREECDFY 83

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

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 568986284   1 MLAHMFKdkGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDgiNLLGVLEEARFFGIDSLIE 68
Cdd:cd18366   29 MLAAMFS--GRHHIPKDSEGRYFIDRDGSYFGYILNFLRDGDLPPRE--RARAVYKEAQYYGIGPLIE 92

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
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 568986284  16 QDHRGAFLIDRSPEYFEPILNYLRHGQLIVNdGINLLGVLEEARFFGIDSLIEHLEV 72
Cdd:cd18393   40 KDETGAIFIDRDPTVFAPILNFLRTKELDPR-GIHVSLLLHEAQFYGITPLVRRLQL 95

Pentapeptide repeats (8 copies); These repeats are found in many cyanobacterial proteins. The repeats were first identified in hglK. The function of these repeats is unknown. The structure of this repeat has been predicted to be a beta-helix. The repeat can be approximately described as A(D/N)LXX, where X can be any amino acid.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 568986284  219 AKLKNCNLRGATLAGTDLENCDLSGCDLQEANLRGSNVKG 258
Cdd:pfam00805   1 ANLSGANLSGANLSGANLSGANLTGANLSGADLSGANLSG 40

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 3 (KCTD3); KCTD3, also called renal carcinoma antigen NY-REN-45, is a BTB/POZ domain-containing protein that is an accessory subunit of potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3), upregulating its cell-surface expression and current density without affecting its voltage dependence and kinetics. 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
                 ....*....|....*....|....*....|....*....|....*...
gi 568986284  16 QDHRGAFLIDRSPEYFEPILNYLRHGQLIVnDGINLLGVLEEARFFGI 63
Cdd:cd18392   40 KDETGAIFIDRDPTAFVPILNFLRTKELDL-RGVNINVLRHEAEFYGI 86

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 21 (KCTD21); KCTD21, also calledz KCTD containing, Cullin3 adaptor, suppressor of Hedgehog 2 (KCASH2), is a BTB/POZ domain-containing protein that 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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 568986284   1 MLAHMFKdkGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLE-EARFFGIDSLIEHLE 71
Cdd:cd18395   26 MLGAMFS--GKFPTKKDSQGNCFIDRDGKIFRYILNFLRTSHLDLPEDFQEMGLLKrEADFYQIQPLIEALQ 95

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 13 (KCTD13); KCTD13, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 1 (BACURD1), or TNFAIP1-like protein, is a BTB/POZ domain-containing protein that may function as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex that mediates the ubiquitination of RhoA, leading to its degradation by the proteasome, thereby regulating the actin cytoskeleton and cell migration. 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 KCTD13 BTB domain forms a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 568986284  17 DHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLG-VLEEARFFGIDSLIEHLEVAIK 75
Cdd:cd18400   40 DSEGWVLIDRSGRHFGTILNYLRDGSVPLPESTRELEeLLGEARYYLVQGLVEDCQLALQ 99

Pentapeptide repeats (8 copies); These repeats are found in many cyanobacterial proteins. The repeats were first identified in hglK. The function of these repeats is unknown. The structure of this repeat has been predicted to be a beta-helix. The repeat can be approximately described as A(D/N)LXX, where X can be any amino acid.

                          10        20        30
                  ....*....|....*....|....*....|....*...
gi 568986284  129 ANLSRCNLAHANLCCANLERADLSGSVLDCANLQGVKM 166
Cdd:pfam00805   1 ANLSGANLSGANLSGANLSGANLTGANLSGADLSGANL 38

Pentapeptide repeats (8 copies); These repeats are found in many cyanobacterial proteins. The repeats were first identified in hglK. The function of these repeats is unknown. The structure of this repeat has been predicted to be a beta-helix. The repeat can be approximately described as A(D/N)LXX, where X can be any amino acid.

                          10        20        30
                  ....*....|....*....|....*....|....*...
gi 568986284  210 NLRVATLKNAKLKNCNLRGATLAGTDLENCDLSGCDLQ 247
Cdd:pfam00805   2 NLSGANLSGANLSGANLSGANLTGANLSGADLSGANLS 39

type III secretion system effector PipB;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568986284 190 NLEGANLKGVDMEGSQMTGINLRVATLKNAKLKNCNLRGATLAGTDLENCDLSGCDLQEANLRGSNVKGAI-FEEML--T 266
Cdd:PRK15197 165 DFQGEDLSDIDASNADFRETTLSNVNLVGANLCCANLHAVNLMGSNMTKANLTHADLTCANMSGVNLTAAIlFGSDLtdT 244

                 ...
gi 568986284 267 PLH 269
Cdd:PRK15197 245 KLN 247

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        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 568986284   1 MLAHMFKdkGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVL-EEARFFGIDSLIEHL 70
Cdd:cd18394   28 MLGAMFR--GDFPTARDSQGNYFIDRDGPLFRYILNFLRTSELTLPVDFKEFDLLrKEADFYQIEPLIQCL 96

Pentapeptide repeats (9 copies);

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 568986284  199 VDMEGSQMTGINLRVATLKNAKLKNCNLRGATLAGTDLENCDLSGCDLQEANLR-----GSNVKGAIFE 262
Cdd:pfam13599   1 ADFTRCSFEGCKLSGTEFYHATLKDCNFTECNLVNVNFDDCNLRDVDFLEAQLKnaqfsGCNLKNSNFS 69

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 14 (KCTD14); KCTD14 is a BTB/POZ domain-containing protein with unknown biological function. 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. 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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568986284   2 LAHMFKdkGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNdgiNLLGVLEEARFFGIDSLIEHLE 71
Cdd:cd18371   28 LAELFN--GQPKLRTDSEGRYFIDRDGTYFRYILEYLRTNQVPTQ---HIQEVYKEALFYDIEPLVKLLE 92

BTB/POZ domain; The BTB (for BR-C, ttk and bab) or POZ (for Pox virus and Zinc finger) domain is present near the N-terminus of a fraction of zinc finger (pfam00096) proteins and in proteins that contain the pfam01344 motif such as Kelch and a family of pox virus proteins. The BTB/POZ domain mediates homomeric dimerization and in some instances heteromeric dimerization. The structure of the dimerized PLZF BTB/POZ domain has been solved and consists of a tightly intertwined homodimer. The central scaffolding of the protein is made up of a cluster of alpha-helices flanked by short beta-sheets at both the top and bottom of the molecule. POZ domains from several zinc finger proteins have been shown to mediate transcriptional repression and to interact with components of histone deacetylase co-repressor complexes including N-CoR and SMRT. The POZ or BTB domain is also known as BR-C/Ttk or ZiN.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 568986284   23 LIDRSPEYFEPILNYLRHGQLIvnDGINLLGVLEEARFFGIDSLIEHLEVAIKNS 77
Cdd:pfam00651  54 LDDVSPEDFEALLEFMYTGKLI--SEENVDDLLAAADKLQIPSLVDKCEEFLIKS 106

Pentapeptide repeats (8 copies); These repeats are found in many cyanobacterial proteins. The repeats were first identified in hglK. The function of these repeats is unknown. The structure of this repeat has been predicted to be a beta-helix. The repeat can be approximately described as A(D/N)LXX, where X can be any amino acid.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 568986284  144 ANLERADLSGSVLDCANLQGVKMLCSNAEGASLRLCNFED 183
Cdd:pfam00805   1 ANLSGANLSGANLSGANLSGANLTGANLSGADLSGANLSG 40

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 568986284   1 MLAHMFK--DKGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLE-EARFF 61
Cdd:cd18370   24 MLGAMFRagTPIPPNLNMQGGGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLRaEADFY 87

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD8, KCTD12, KCTD16 and similar proteins; This subfamily of KCTD proteins includes KCTD8, KCTD12 (also called predominantly fetal expressed T1 domain/Pfetin), and KCTD16. They act as auxiliary subunits of GABAB receptors associated with mood disorders. KCTD8 interacts as a tetramer with GABRB1 and GABRB2. KCTD12 regulates agonist potency and kinetics of GABAB receptor signaling. It promotes tumorigenesis by facilitating CDC25B/CDK1/Aurora A-dependent G2/M transition. KCTD16 interacts with amyloid beta precursor protein (APP), a type I transmembrane protein involved in a variety of cellular processes such as cell adhesion, and axon guidance. 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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 568986284   1 MLAHMFKDKGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLE-EARFFGIDSLIEHL 70
Cdd:cd18367   28 LLGRMFSGKNRQELARDSKGRYFLDRDGVLFRYILDYLRNQKLVLPENFPERERLKrEAEYFQLPELVKAL 98

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 568986284  22 FLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLEEARFFGIDSL 66
Cdd:cd18424   50 YFFDRSSQAFKYIMNYYKTGHLHVMEELCAISFLQEIEYWGIDEL 94

Pentapeptide repeats (9 copies);

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 568986284  179 CNFEdpsglKANLEGANLKGVDMEGSQMTGINLRVATLKNAKLKNCNLRGATLAGTDLENCDLSGCDLQEANL 251
Cdd:pfam13599  11 CKLS-----GTEFYHATLKDCNFTECNLVNVNFDDCNLRDVDFLEAQLKNAQFSGCNLKNSNFSDVKLKGADF 78

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 12 (KCTD12); KCTD12, also called predominantly fetal expressed T1 domain (Pfetin), is a BTB/POZ domain-containing protein that is an auxiliary subunit of GABAB receptors associated with mood disorders. It regulates agonist potency and kinetics of GABAB receptor signaling. It promotes tumorigenesis by facilitating CDC25B/CDK1/Aurora A-dependent G2/M transition. It also regulates colorectal cancer cell stemness through the ERK pathway. 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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 568986284   1 MLAHMFKDKGVWGNKQDHRGAFLIDRSPEYFEPILNYLRHGQLIVNDGINLLGVLE-EARFFGIDSLIEHL 70
Cdd:cd18397   28 LLWHMFSQQKPGELARDSKGRFFLDRDGFLFRYILDYLRDLQLVLPDYFPERSRLQrEAEFFQLPELVKRL 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 10 (KCTD10); KCTD10, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 3 (BACURD3), is a BTB/POZ domain-containing protein that interacts with proliferating cell nuclear antigen (PCNA) and polymerase delta, and participates in DNA repair, DNA replication, and cell-cycle control. Its down-regulation could inhibit cell proliferation. KCTD10 also plays crucial roles in embryonic angiogenesis and heart development in mammals by negatively regulating the Notch signaling pathway. Furthermore, KCTD10 may function as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex, which mediates the ubiquitination of target proteins, leading to their degradation by the proteasome. 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 KCTD10 BTB domain forms a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 568986284  17 DHRGAFLIDRSPEYFEPILNYLRHGQL-IVNDGINLLGVLEEARFFGIDSLIEHLEVAIKNSQPPE 81
Cdd:cd18399   45 DSEGWILIDRCGKHFGTILNYLRDGAVpLPESRREIEELLAEAKYYLVQGLVEECQAALQNKDTYE 110

type III secretion system effector HECT-type E3 ubiquitin transferase;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568986284  65 SLIEHLEVAIKNSQPPEDHSPISRKEFVRFLLATPTKSELRCQGlnfSGADLSRLDLRYINFKMANLSRCNLAHANLCCa 144
Cdd:PRK15377  86 KNIKDTNNAGKKNISAEDVSKMNAAFMRKHIANQTCDYNYRITG---AAPLPGGVSVSANNRPTVSEGRTPPVSPSLSL- 161

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568986284 145 nLERADLSGSVLDCANLQGVKMLCSNAEGASLRLCNFEDPSGLKANLEGANLKG-VDMEGSQMTGINLRVATLKNAKLKN 223
Cdd:PRK15377 162 -QATSSPSSPADWAKKLTDARLRQEAGEELTYADRDFSNADFRNINFSKINPSGfMLRDGDIIKGFNFSNSKFTYSDISH 240

                        170       180       190
                 ....*....|....*....|....*....|....*.
gi 568986284 224 -----CNLRGATLAGTDLENCDLSGCDLQEANLRGS 254
Cdd:PRK15377 241 lhfdeCRFTYSTLSDVVCSNTKFSNSDMNEASLKYS 276

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
                 ....*....|....*....|....*....|....*....|....*...
gi 568986284  20 GAFLIDRSPEYFEPILNYLRHGQLivNDGINLLGVL--EEARFFGIDS 65
Cdd:cd18379   43 GEFFFDRHPGVFAQILNYYRTGKL--HCPADVCGPLfeEELAFWGIDE 88

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 568986284  13 GNKQDHR---GAFLIDRSPEYFEPILNYLRHGQLIVNDGI-NLLGVLEEARFFGIDSLIEHLE 71
Cdd:cd18375   33 GKDQDFKvvnGQFFVDRDGSLFSYILDYLRTGQLTLPTEFsDYNRLAREAEFYGLYSLADLLS 95

Pentapeptide repeats (9 copies);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 568986284  173 GASLRLCNFEDPSGLKANLEGANLKGVDMEGSQMTGINLRVATLKNAKLKNCNLRGATL 231
Cdd:pfam13599  20 HATLKDCNFTECNLVNVNFDDCNLRDVDFLEAQLKNAQFSGCNLKNSNFSDVKLKGADF 78