BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 2 (BTBD2); BTBD2 is a BTB-domain-containing Kelch-like protein that interacts with DNA topoisomerase 1 (Topo1), a key enzyme in cell survival. BTBD1 and BTBD2 colocalize to cytoplasmic bodies with the RBCC/tripartite motif protein, TRIM5delta.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932  69 LRADNAFMLLTQARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGIREVRLFNAVVRWSEAECQR 148
Cdd:cd18523     1 LRADNAFMLLTQARLFDEPQLASLCLENIDKNTSDAINAEGFTDIDLDTLVAVLERDTLGIREVRLFNAVVRWAEAECQR 80

                          90       100
                  ....*....|....*....|....*.
gi 2217321932 149 QQLQVTPENRRKVLGKALGLIRFPLM 174
Cdd:cd18523    81 QQLQVTPENKRKVLGKALSLIRFPLM 106

BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 2 (BTBD2); BTBD2 is a BTB-domain-containing Kelch-like protein that interacts with DNA topoisomerase 1 (Topo1), a key enzyme in cell survival. BTBD1 and BTBD2 colocalize to cytoplasmic bodies with the RBCC/tripartite motif protein, TRIM5delta.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932  69 LRADNAFMLLTQARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGIREVRLFNAVVRWSEAECQR 148
Cdd:cd18523     1 LRADNAFMLLTQARLFDEPQLASLCLENIDKNTSDAINAEGFTDIDLDTLVAVLERDTLGIREVRLFNAVVRWAEAECQR 80

                          90       100
                  ....*....|....*....|....*.
gi 2217321932 149 QQLQVTPENRRKVLGKALGLIRFPLM 174
Cdd:cd18523    81 QQLQVTPENKRKVLGKALSLIRFPLM 106

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        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932   1 MFNGGMAT-TSTEIELPDVEPAAFLALLKFLYSDEVqIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNL 69
Cdd:pfam00651  39 LFSGQESEsSVSEITLDDVSPEDFEALLEFMYTGKL-ISEENVDDLLAAADKLQIPSLVDKCEEFLIKSL 107

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
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932    1 MFNGGMA-TTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNL 69
Cdd:smart00225  28 LFSSDFKeSDKSEIYLDDVSPEDFRALLNFLYTGKLDLPEENVEELLELADYLQIPGLVELCEEFLLKLL 97

BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 2 (BTBD2); BTBD2 is a BTB-domain-containing Kelch-like protein that interacts with DNA topoisomerase 1 (Topo1), a key enzyme in cell survival. BTBD1 and BTBD2 colocalize to cytoplasmic bodies with the RBCC/tripartite motif protein, TRIM5delta.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932  69 LRADNAFMLLTQARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGIREVRLFNAVVRWSEAECQR 148
Cdd:cd18523     1 LRADNAFMLLTQARLFDEPQLASLCLENIDKNTSDAINAEGFTDIDLDTLVAVLERDTLGIREVRLFNAVVRWAEAECQR 80

                          90       100
                  ....*....|....*....|....*.
gi 2217321932 149 QQLQVTPENRRKVLGKALGLIRFPLM 174
Cdd:cd18523    81 QQLQVTPENKRKVLGKALSLIRFPLM 106

BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 1 (BTBD1); BTBD1, also called Hepatitis C virus NS5A-transactivated protein 8 or HCV NS5A-transactivated protein 8, is a BTB-domain-containing Kelch-like protein specifically expressed in skeletal muscle. It interacts with DNA topoisomerase 1 (Topo1), a key enzyme in cell survival. BTBD1 and BTBD2 colocalize to cytoplasmic bodies with the RBCC/tripartite motif protein, TRIM5delta. It may serve as a substrate-specific adaptor of an E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932  69 LRADNAFMLLTQARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGIREVRLFNAVVRWSEAECQR 148
Cdd:cd18522     1 LRADNAFMLLTQARLFDEPQLASLCLDTIDKSTMDAISAEGFTDIDLDTLCAVLERDTLSIRESRLFGAVVRWAEAECQR 80

                          90       100
                  ....*....|....*....|....*..
gi 2217321932 149 QQLQVTPENRRKVLGKALGLIRFPLMT 175
Cdd:cd18522    81 QQLPVTSENKQKVLGKALSLIRFPLMT 107

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in BTB/POZ domain-containing protein 1 (BTBD1); BTBD1, also called Hepatitis C virus NS5A-transactivated protein 8 or HCV NS5A-transactivated protein 8, is a BTB-domain-containing Kelch-like protein that is expressed in skeletal muscle and interacts with DNA topoisomerase 1 (Topo1), a key enzyme of cell survival. BTBD1 and BTBD2 colocalize to cytoplasmic bodies with the RBCC/tripartite motif protein, TRIM5delta. BTBD1 may serve as substrate-specific adaptor of an E3 ubiquitin-protein ligase complex that mediates the ubiquitination and subsequent proteasomal degradation of target proteins. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217321932   1 MFNGGMATTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADN 73
Cdd:cd18346    61 MFNGGMATTSAEIELPDVEPAAFLALLRFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLTKHLRADN 133

BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing proteins, BTBD3 and BTBD6; This subfamily includes BTB/POZ domain-containing proteins BTBD3 and BTBD6, both of which are BTB-domain-containing Kelch-like proteins. BTBD3 controls dendrite orientation toward active axons in mammalian neocortex. BTBD6 is required for proper embryogenesis and plays an essential evolutionarily-conserved role during neuronal development.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932  69 LRADNAFMLLTQARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGIREVRLFNAVVRWSEAECQR 148
Cdd:cd18488     1 LSARNACVLLSQSRLFEEPELMQRCWEVIDAQAELALKSEGFTEIDYKTLESILRRETLNAKESVVFEAALRWAEAECQR 80

                          90
                  ....*....|....*
gi 2217321932 149 QQLQVTPENRRKVLG 163
Cdd:cd18488    81 RGLEPTPENKRKVLG 95

BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 3 (BTBD3); BTBD3 is a BTB-domain-containing Kelch-like protein that controls dendrite orientation toward active axons in mammalian neocortex.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932  69 LRADNAFMLLTQARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGIREVRLFNAVVRWSEAECQR 148
Cdd:cd18524     1 LSAKNACVLLSQSCLFEEPDLTQRCWEVIDAQAELALKSEGFCDIDFQTLESILRRETLNAKEIVVFEAALNWAEVECQR 80

                          90
                  ....*....|....*
gi 2217321932 149 QQLQVTPENRRKVLG 163
Cdd:cd18524    81 QELQPTIENKRKVLG 95

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in BTB/POZ domain-containing protein 6 (BTBD6); BTBD6, also termed lens BTB domain protein, is a BTB-domain-containing Kelch-like protein required for proper embryogenesis and plays an essential evolutionary conserved role during neuronal development. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217321932   1 MFNGGMATTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNL 69
Cdd:cd18349    41 MFYGDLAEVKSEIHIPDVEPAAFLILLKYMYSDEIDLEADTVLATLYAAKKYIVPALAKACVNFLETSL 109

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        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932   1 MFNGGMAT-TSTEIELPDVEPAAFLALLKFLYSDEVqIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNL 69
Cdd:pfam00651  39 LFSGQESEsSVSEITLDDVSPEDFEALLEFMYTGKL-ISEENVDDLLAAADKLQIPSLVDKCEEFLIKSL 107

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
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932    1 MFNGGMA-TTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNL 69
Cdd:smart00225  28 LFSSDFKeSDKSEIYLDDVSPEDFRALLNFLYTGKLDLPEENVEELLELADYLQIPGLVELCEEFLLKLL 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing (ZBTB) proteins, Kelch-like (KLHL) proteins, and similar proteins; This family includes a variety of BTB/POZ domain-containing proteins, such as zinc finger and BTB domain-containing (ZBTB) proteins and Kelch-like (KLHL) proteins. They 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. These special additional domains or interaction partners provide unique characteristics and functions to BTB/POZ proteins. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 2217321932   1 MFNGGMAT-TSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKY 52
Cdd:cd18186    30 MFSSGMKEsSSSEIELDDVSPEAFEALLDYIYTGELELSEENVEELLAAADKL 82

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 7 (KLHL7); KLHL7 is a component of a Cul3-based E3 ubiquitin ligase complex and is involved in the ubiquitination of target proteins for proteasome-mediated degradation. Mutations in KLHL7 causes autosomal-dominant retinitis pigmentosa. It contains a BTB domain and kelch repeats, characteristics of a kelch family protein. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217321932   1 MFNGGMATTST-EIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADN 73
Cdd:cd18237    50 MFTSNMTESKSsEVELKDAEPDIIELLVEFAYTARISVNSNNVQSLLDAANQYQIEPVKKMCVDFLKEQLDASN 123

BTB And C-terminal Kelch; This domain is found associated with pfam00651 and pfam01344. The BACK domain is found juxtaposed to the BTB domain; they are separated by as little as two residues. This family appears to be closely related to the BTB domain (Finn RD, personal observation).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932  81 ARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGI-REVRLFNAVVRWseaecqrqqLQVTPENRR 159
Cdd:pfam07707   8 ADAYGCTELAEAALRFILQNFLEVAKSEEFLELSLEQLLELLSSDDLNVpSEEEVFEAVIRW---------VKHDVERRK 78

                          90
                  ....*....|....*.
gi 2217321932 160 KVLGKALGLIRFPLMT 175
Cdd:pfam07707  79 KHLPELLSAVRLPLLS 94

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 8 (KLHL8); KLHL8 is a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin ligase complex required for the ubiquitination and degradation of rapsyn, a postsynaptic protein required for clustering of nicotinic acetylcholine receptors (nAChRs) at the neuromuscular junction. It contains a BTB domain and kelch repeats, characteristics of a kelch family protein. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217321932   1 MFNGGMA-TTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADNA 74
Cdd:cd18238    44 MFTSEMAeSKQDSITIKDIDEEAVELLVDFAYTGKLTLTVDNVQSLLYAASLLQVEEVAKACCEFMKDHLHPSNC 118

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in BTB/POZ domain-containing protein 9 (BTBD9); BTBD9 is a risk factor for Restless Legs Syndrome (RLS) encoding a Cullin-3 substrate adaptor. The BTBD9 gene may be associated with antipsychotic-induced RLS in schizophrenia. Mutations in BTBD9 lead to reduced dopamine, increased locomotion and sleep fragmentation. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217321932   1 MFNGGMA-TTSTEIELPDVEPAAFLALLKFLYSDEVQIG---PETVMTTLYTAKKYAVPALEAHCVEFL 65
Cdd:cd18287    51 LLYGGMReSQQSEIELKDTNAEAFKALLKYIYTGRLTLTdlkEDVLLDVLGLAHQYGFEELEAAISDYL 119

BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 17 (BTBD17); BTBD17, also termed galectin-3-binding protein-like, is a BTB-domain-containing Kelch-like protein. Its function remains unclear. It may be involved in hepatocellular carcinoma development and progression.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217321932  78 LTQARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGIR-EVRLFNAVVRW 141
Cdd:cd18493     9 LQYAKMCGHKELAEACLEFIAWNFEKVLKSPDWLNLDLDLLVSLLQSSDLVVEdEYTLFQAVEKW 73

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Ankyrin repeat and BTB/POZ domain-containing protein 2 (ABTB2) and similar proteins; This family includes ABTB2, BTBD11, plant ARM repeat protein interacting with ABF2 (ARIA), and similar proteins. ABTB2, also called bood POZ containing gene type 2 (BPOZ-2), is a scaffold protein that controls the degradation of many biological proteins ranging from embryonic development to tumor progression. It may be involved in the initiation of hepatocyte growth. ABTB2 functions as an adaptor protein for the E3 ubiquitin ligase scaffold protein Cullin-3. It directly binds to eukaryotic elongation factor 1A1 (eEF1A1) to promote eEF1A1 ubiquitylation and degradation, and prevent translation. The BTBD11 gene has been recently identified as an all-trans retinoic acid (atRA)-responsive gene that lies downstream of atRA and its receptors in the regulation of neurite outgrowth and cell adhesion in neural as well as non-neural tissues. ARIA is an armadillo (ARM) repeat and BTB domain-containing protein that acts as a positive regulator of ABA response via the modulation of the transcriptional activity of ABF2. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217321932   1 MFNGGMATTS-TEIELPDVEPAAFLALLKFLYS---DEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADN 73
Cdd:cd18297    41 MLSSGSTEAQtPVIEIPDIRYDIFQLMMQYLYTggvESLDVAQDDALELLRAASFFQLDGLKRHCEILLSQQIDLDN 117

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 41 (KLHL41); KLHL41 is also called Kel-like protein 23, Kelch repeat and BTB domain-containing protein 10 (KBTBD10), Kelch-related protein 1 (Krp1), or sarcosine. It is a novel kelch-related protein that is involved in pseudopod elongation in transformed cells. It is also involved in skeletal muscle development and differentiation. It regulates proliferation and differentiation of myoblasts and plays a role in myofibril assembly by promoting lateral fusion of adjacent thin fibrils into mature, wide myofibrils. It contains a BTB domain and kelch repeats, characteristics of a kelch family protein. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217321932  12 EIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADN 73
Cdd:cd18341    68 EVVLDNVDPNIMDMILKYLYSAEIDLNDGNVQDIFALASRFQIPSVFTVCVTYLQKRLSPAN 129

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like proteins KLHL1, KLHL4 and KLHL5; This family contains the Kelch-like proteins: KLHL1, KLHL4 and KLHL5, all of which share high identity and similarity with the Drosophila kelch protein, a component of ring canals. KLHL1 is a neuronal actin-binding protein that modulates voltage-gated CaV2.1 (P/Q-type) and CaV3.2 (alpha1H T-type) calcium channels. Family members contain a BTB domain and kelch repeat domains, characteristics of a kelch family protein. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217321932   1 MFNGGM-ATTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADN 73
Cdd:cd18234    30 MFTNDVrEATEEEIKLKDVDPDALWTLVQYCYTGRLELKEDNVESLLATACLLQLSEVVEACCGFLMKQLHPSN 103

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 18 (KLHL18); KLHL18 acts as a substrate-specific adaptor for a Cullin3 E3 ubiquitin-protein ligase complex that regulates mitotic entry and ubiquitylates Aurora-A. It contains a BTB domain and kelch repeats, characteristics of a kelch family protein. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217321932   1 MFNGGMA-TTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKK 67
Cdd:cd18247    48 MFTHDMVeSKQDEITMQGIEPSALEALINFAYSGRIAIDTSNVQSLLVGASFLQLQSVKDACCEFLKE 115

BACK (BTB and C-terminal Kelch) domain found in BTB/POZ domain-containing protein 19 (BTBD19); BTBD19 is a BTB-domain-containing Kelch-like protein. Its function remains unclear.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217321932  72 DNAFMLLTQARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGIREVRLFNAVVRWS 142
Cdd:cd18494     3 ETACEALQAAVTYGQDELKERCLAFIEEHTEEVFKTKGFHELSDEALSVILRSDKLRIDELDILKAVREWA 73

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in rabankyrin-5 (Rank-5); Rank-5, also called ankyrin repeat and FYVE domain-containing protein 1 (ANKFY1) or ankyrin repeats hooked to a zinc finger motif (ANKHZN), is a Rab5 effector that regulates and coordinates different endocytic mechanisms. It contains an N-terminal BTB domain, followed by a BACK domain, several ankyrin (ANK) repeats and a C-terminal FYVE domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217321932  12 EIELPDVEPAAFLALLKFLYSDEVQIG--PETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADN 73
Cdd:cd18303    54 ELDLSDISYEVVLALLRWLYTDELDLTldDEFLLELMKAAKRFQLTDLVERCERALMSSVNVDN 117

BACK (BTB and C-terminal Kelch) domain found in Kelch-like protein 7 (KLHL7); KLHL7 is a BTB-Kelch protein that constitutes a Cul3-based E3 ubiquitin ligase complex and is involved in the ubiquitination of target proteins for proteasome-mediated degradation. Mutations in KLHL7 cause autosomal-dominant retinitis pigmentosa.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932  71 ADNAFMLLTQARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGIR-EVRLFNAVVRWseaecqrq 149
Cdd:cd18447     4 ASNCLGISVLAECLDCPELKATADDFIHQHFTEVYKTDEFLQLDVKRVTHLLNQDTLTVRaEDQVYDAAVRW-------- 75

                          90       100
                  ....*....|....*....|....
gi 2217321932 150 qLQVTPENRRKVLGKALGLIRFPL 173
Cdd:cd18447    76 -LKYDEPNRQPYMVDILAKVRFPL 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in BTB/POZ domain-containing protein 17 (BTBD17); BTBD17, also called galectin-3-binding protein-like, is a BTB domain-containing protein. Its function remains unclear. It may be associated with hepatocellular carcinoma. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 2217321932  11 TEIELpdVEP----AAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEF 64
Cdd:cd18292    58 SEIEL--VEDpecaAVFEKFLRYLYTGQISVNLETALPLLMLADKYNVTDLKQLCVDF 113

BACK (BTB and C-terminal Kelch) domain found in Kelch-like proteins, KLHL9 and KLHL13; KLHL9 and KLHL13 (also termed BTB and kelch domain-containing protein 2, or BKLHD2) are substrate-specific adaptors of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex required for mitotic progression and cytokinesis. The BCR(KLHL9-KLHL13) E3 ubiquitin ligase complex mediates the ubiquitination of AURKB and controls the dynamic behavior of AURKB on mitotic chromosomes and thereby coordinates faithful mitotic progression and completion of cytokinesis.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217321932  97 IDKNTADAITAEGFTDIDLDTLVAVLERDTL-GIREVRLFNAVVRWSEAEcqrqqlqvtpENRRKVLGKALGLIRFP 172
Cdd:cd18449    29 ILKNFPALLSTGDFVKLPFERLAFVLSSNSLkGCTELELFKAACRWLRHE----------DDRMQFAAKLMENIRFP 95

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 12 (KLHL12); KLHL12, also called CUL3-interacting protein 1 (C3IP1) or DKIR homolog, is a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin ligase complex that acts as a negative regulator of the Wnt signaling pathway and ER-Golgi transport. It contains a BTB domain and kelch repeats, characteristics of a kelch family protein. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217321932   1 MFNGGMA-TTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADN 73
Cdd:cd18242    50 MFTSEMSeKGKSEVELQGLTASTMEILLDFVYTETVHVTVENVQELLPAACLLQLKGVKQACCEFLESQLDPSN 123

BACK (BTB and C-terminal Kelch) domain found in Kelch-like protein 41 (KLHL41); KLHL41, also called Kel-like protein 23, or Kelch repeat and BTB domain-containing protein 10, or Kelch-related protein 1 (Krp1), or sarcosine, is a novel kelch related protein that is involved in pseudopod elongation in transformed cells. It is also involved in skeletal muscle development and differentiation. It regulates proliferation and differentiation of myoblasts and plays a role in myofibril assembly by promoting lateral fusion of adjacent thin fibrils into mature, wide myofibrils.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932  69 LRADNAFMLLTQARLFDEPQLASLCLENIDKNTADAITAEGFTDIDLDTLVAVLERDTLGI-REVRLFNAVVRWseaecq 147
Cdd:cd18517     1 LSVGNCLAIFRLGLLLDCPRLAVSARDFVSDRFEQISKEEDFLQLAPHELIAIISSDSLNVeKEELVFEAVMKW------ 74

                          90       100
                  ....*....|....*....|....*...
gi 2217321932 148 rqqLQVTPENRRKVLGKALGLIRFPLMT 175
Cdd:cd18517    75 ---VRTDKENRVKSLGEIFDCIRFRLMP 99

BACK (BTB and C-terminal Kelch) domain found in Kelch-like protein 26 (KLHL26); KLHL26 is a kelch family protein encoded by gene klhl26, which is regulated by p53 via fuzzy tandem repeats.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932  89 LASLclenidKNTADAIT---------AEGFTDIDLDTLVAVLERDTL-GIREVRLFNAVVRWseaecqrqqLQVTPeNR 158
Cdd:cd18465    18 LASL------KESVDAFTfrhflqiaeEEDFLHLPLERLVFFLQSNKLkNCSEIDLFRAAIRW---------LQHDP-SR 81

                          90
                  ....*....|....*.
gi 2217321932 159 RKVLGKALGLIRFPLM 174
Cdd:cd18465    82 RASASHVLCHIRFPLM 97

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
                  ....*....|....*....|....*....|....*....|....*....|...
gi 2217321932   1 MFNGGMATTS-TEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKY 52
Cdd:cd01165    27 LFRGGFRESGqAEINLRDISPEDFRALLEFLYGGKRDLDASNLLELLEAANFL 79

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 35 (KLHL35); KLHL35 contains a BTB domain and kelch repeats, characteristics of a kelch family protein. Its function remains unclear. Significant differences in DNA methylation of the KLHL35 gene in abdominal aortic aneurysm (AAA) patients compared to non-AAA controls suggest a potential role in AAA pathology. Hypermethylation of the KLHL35 gene has also been associated with the development of hepatocellular carcinoma. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217321932   1 MFNGGMATTSTE-IELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADN 73
Cdd:cd18265    52 MFGGHLKESRQAvVEIQKVSAAAMEVLLDYMYGGGLRIQEDNVESVLEASDLLQVSKLREACVRFLEGQLHPCN 125

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in speckle-type POZ protein (SPOP); SPOP, also called HIB homolog 1 or Roadkill homolog 1, is a novel nuclear speckle-type protein which serves as an adaptor of a cullin-RING-based BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex that mediates the ubiquitination and proteasomal degradation of target proteins, such as BRMS1, DAXX, PDX1/IPF1, GLI2 and GLI3. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217321932   1 MFNGGMA-TTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADNA 74
Cdd:cd18342    51 MFEHEMEeSKKNRVEINDVEPEVFKEMMCFIYTGKAPNLDKMADDLLAAADKYALERLKVMCEDALCSNLSVENA 125

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in speckle-type POZ protein-like (SPOPL); SPOPL, also called HIB homolog 2 or Roadkill homolog 2, is a component of a cullin-RING-based BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complexes that mediate the ubiquitination and subsequent proteasomal degradation of target proteins. The complexes may contain homodimeric SPOPL or the heterodimers formed by speckle-type POZ protein (SPOP) and SPOPL, which are less efficient than ubiquitin ligase complexes containing only SPOP. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217321932   1 MFNGGMA-TTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADN 73
Cdd:cd18343    50 MFEHEMEeSKKNRVEINDVDPEVFKEMMRFIYTGKAPNLDKMADNLLAAADKYALERLKVMCEEALCNNLSVEN 123

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 3 (KLHL3); KLHL3 is a component of an E3 ubiquitin ligase complex that regulates blood pressure by targeting With-No-Lysine (WNK) kinases for degradation. It contains a BTB domain and kelch repeat domains, characteristics of a kelch family protein. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217321932   1 MFNGGMA-TTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNL 69
Cdd:cd18339    50 MFTGDMSeSKAKKIEIKDVDGQTLSKLIDYIYTAEIEVTEENVQVLLPAASLLQLMDVRQNCCDFLQSQL 119

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch repeat and BTB domain-containing protein 8 (KBTBD8); KBTBD8, also called T-cell activation kelch repeat protein (TA-KRP), is a BTB-kelch family protein that is located in the Golgi apparatus and translocates to the spindle apparatus during mitosis. It acts as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin ligase complex that acts as a regulator of neural crest specification. The BCR(KBTBD8) complex monoubiquitylates NOLC1 and its paralog TCOF1, the mutation of which underlies the neurocristopathy Treacher Collins syndrome. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217321932   1 MFNGGMA-TTSTEIELPDVEPAAFLALLKFLYSDEVQIGPETVMTTLYTAKKYAVPALEAHCVEFLKKNLRADNA 74
Cdd:cd18274    52 MFTSGLTeSTQKEVRIVGVEAESMHLVLDYAYTSRVTLTEANVQALFTAASIFQIPSLQDQCAQFMISRLDPQNS 126