BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain superfamily; Proteins in this superfamily are characterized by the presence of a common protein-protein interaction motif of about 100 amino acids, known as the BTB/POZ domain. Members include transcription factors, oncogenic proteins, ion channel proteins, and potassium channel tetramerization domain (KCTD) proteins. They have been identified in poxviruses and many eukaryotes, and have diverse functions, such as transcriptional regulation, chromatin remodeling, protein degradation and cytoskeletal regulation. Many BTB/POZ proteins contain one or two additional domains, such as kelch repeats, zinc-finger domains, FYVE (Fab1, YOTB, Vac1, and EEA1) fingers, or ankyrin repeats, among others. These special additional domains or interaction partners provide unique characteristics and functions to BTB/POZ proteins. In ion channel proteins and KCTD proteins, the BTB/POZ domain is also called the tetramerization (T1) domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 254 RGDLGELPFPCPDGfSSCPDICFRVADSSFLCYKAFFCGRSDYFRALLDDHFQESEEpaASGDPPVVTLHDISPDIFIHV 333
Cdd:cd18296     1 RVDLDELPFPPEQE-LSFPDVCFQVEGHRFPCHKAFFCGRSDYFKALLRDHFAESEE--NNGSIPVVTLHDVSPEVFAIV 77

                          90
                  ....*....|.
gi 2289442709 334 LYYVYSDHTEL 344
Cdd:cd18296    78 LYYIYTDDTDL 88

BACK (BTB and C-terminal Kelch) domain; The BACK domain is found in architectures C-terminal to a BTB domain, in a diverse set of architectures together with Kelch, MATH, and/or TAZ domains. It is involved in interactions with the Cullin3 (Cul3) ubiquitin ligase complex, as well as in homo-oligomerization. Most proteins containing the BACK domain are understood to function as adaptor proteins that play a role in ubiquitination of various substrates.

                          10        20        30
                  ....*....|....*....|....*....|....*...
gi 2289442709 343 ELVEREDFVEAVREEAAAVAARQETDSIPLVDDIRFHV 380
Cdd:cd18497    35 ELVDDEEFAELVREDAASVKNRQETDSIPIIDDIRYHL 72

second BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Ankyrin repeat and BTB/POZ domain-containing protein 1 (ABTB1); ABTB1, also called elongation factor 1A-binding protein or bood POZ containing gene type 1 (BPOZ-1), is an anti-proliferative factor that may act as a mediator of the phosphatase and tensin homolog (PTEN) growth-suppressive signaling pathway. It may play a role in developmental processes. ABTB1 contains an ankyrin repeat and two BTB domains. This model corresponds to the second BTB domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 254 RGDLGELPFPCPDGfSSCPDICFRVADSSFLCYKAFFCGRSDYFRALLDDHFQESEEpaASGDPPVVTLHDISPDIFIHV 333
Cdd:cd18296     1 RVDLDELPFPPEQE-LSFPDVCFQVEGHRFPCHKAFFCGRSDYFKALLRDHFAESEE--NNGSIPVVTLHDVSPEVFAIV 77

                          90
                  ....*....|.
gi 2289442709 334 LYYVYSDHTEL 344
Cdd:cd18296    78 LYYIYTDDTDL 88

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 2289442709  116 DVVFVVHGKPFRAHRCILGARSTYFANMLDTKWK--GKSVVVLRHplINPVAFGALLQYLYTGRLDIGVEHVSDCERLAK 193
Cdd:smart00225   1 DVTLVVGGKKFHAHKAVLAAHSPYFKALFSSDFKesDKSEIYLDD--VSPEDFRALLNFLYTGKLDLPEENVEELLELAD 78

                           90
                   ....*....|....*..
gi 2289442709  194 QCQLWDLLDDLEAKCEK 210
Cdd:smart00225  79 YLQIPGLVELCEEFLLK 95

Ankyrin repeats (3 copies);

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709   6 LFASCRKGDVGRVRYLLEQRDVEVNVRDKwdsTPLYYACLCGHEELVRYLLANGARCEAN 65
Cdd:pfam12796  34 LHLAAKNGHLEIVKLLLEHADVNLKDNGR---TALHYAARSGHLEIVKLLLEKGADINVK 90

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 2289442709 273 DICFRVADSSFLCYKAFFCGRSDYFRALLDDHFQESEEpaasgdpPVVTLHDISPDIFIHVLYYVYSDHTE 343
Cdd:pfam00651  12 DVTLVVGDKEFRAHKAVLAACSPYFKALFSGQESESSV-------SEITLDDVSPEDFEALLEFMYTGKLI 75

ankyrin repeat protein; Provisional

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 2289442709  17 RVRYLLEQrDVEVNVRDKWDSTPLYYACLCGHEELVRYLLANGARCEANTFDGERCL 73
Cdd:PHA03100  174 RVNYLLSY-GVPINIKDVYGFTPLHYAVYNNNPEFVKYLLDLGANPNLVNKYGDTPL 229

hypothetical protein; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 105 LQRLLEQGIHSDVVFVV-HGKPFRAHRCILGARSTYFANMLDTKWKGKSVVV-LRHPLINPVAFGALLQYLYTgrldigv 182
Cdd:PHA02713   16 ISNLLDDDILCDVIITIgDGEEIKAHKTILAAGSKYFRTLFTTPMIIRDLVTrVNLQMFDKDAVKNIVQYLYN------- 88

                          90       100
                  ....*....|....*....|....*...
gi 2289442709 183 EHVSDCERL-AKQCQLWDLLDDLEAKCE 209
Cdd:PHA02713   89 RHISSMNVIdVLKCADYLLIDDLVTDCE 116

second BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Ankyrin repeat and BTB/POZ domain-containing protein 1 (ABTB1); ABTB1, also called elongation factor 1A-binding protein or bood POZ containing gene type 1 (BPOZ-1), is an anti-proliferative factor that may act as a mediator of the phosphatase and tensin homolog (PTEN) growth-suppressive signaling pathway. It may play a role in developmental processes. ABTB1 contains an ankyrin repeat and two BTB domains. This model corresponds to the second BTB domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 254 RGDLGELPFPCPDGfSSCPDICFRVADSSFLCYKAFFCGRSDYFRALLDDHFQESEEpaASGDPPVVTLHDISPDIFIHV 333
Cdd:cd18296     1 RVDLDELPFPPEQE-LSFPDVCFQVEGHRFPCHKAFFCGRSDYFKALLRDHFAESEE--NNGSIPVVTLHDVSPEVFAIV 77

                          90
                  ....*....|.
gi 2289442709 334 LYYVYSDHTEL 344
Cdd:cd18296    78 LYYIYTDDTDL 88

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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 105 LQRLLEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPLINPVAFGALLQYLYTGRLDIGveh 184
Cdd:pfam00651   1 LNELREQGELCDVTLVVGDKEFRAHKAVLAACSPYFKALFSGQESESSVSEITLDDVSPEDFEALLEFMYTGKLISE--- 77

                          90       100
                  ....*....|....*....|....*...
gi 2289442709 185 vsdcERLAKQCQLWDLL--DDLEAKCEK 210
Cdd:pfam00651  78 ----ENVDDLLAAADKLqiPSLVDKCEE 101

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 2289442709  116 DVVFVVHGKPFRAHRCILGARSTYFANMLDTKWK--GKSVVVLRHplINPVAFGALLQYLYTGRLDIGVEHVSDCERLAK 193
Cdd:smart00225   1 DVTLVVGGKKFHAHKAVLAAHSPYFKALFSSDFKesDKSEIYLDD--VSPEDFRALLNFLYTGKLDLPEENVEELLELAD 78

                           90
                   ....*....|....*..
gi 2289442709  194 QCQLWDLLDDLEAKCEK 210
Cdd:smart00225  79 YLQIPGLVELCEEFLLK 95

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in BTB/POZ domain-containing protein 19 (BTBD19); BTBD19 is a BTB domain-containing protein. Its function remains unclear. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2289442709 105 LQRLLEQGIHSDVVFVV--HGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVlRHPL--INPVAFGALLQYLYTGRL 178
Cdd:cd18294     5 MKSLINNPEFSDVKFLVgpERQEIFAHKCILAARCEVFRAMFLTGPQKESTQS-PLVLsdIEPEVFRAVLEFIYTNCV 81

BTB (Broad-Complex, Tramtrack and Bric a brac) /POZ (poxvirus and zinc finger) domain found in Dictyostelium discoideum trishanku and similar proteins; Trishanku is a novel regulator required for normal morphogenesis and cell-type stability in Dictyostelium discoideum. It contains a BTB domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 115 SDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSV--VVLRHplINPVAFGALLQYLYTGRLDIGVEHVSDCERLA 192
Cdd:cd18314     7 SDVVLCVGDRKFFAHRIVLCARSPVFRSMLTGSMIESNLkeVTLED--VEPEIFETVLKYMYTGQVTLSEENVLDLLMLA 84

                  ....*....
gi 2289442709 193 KQCQLWDLL 201
Cdd:cd18314    85 SKYQVPDLE 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in RCC1 and BTB domain-containing proteins, RCBTB1 and RCBTB2; The RCC1-related guanine nucleotide exchange factor (GEF) family includes RCC1 and BTB domain-containing proteins, RCBTB1 and RCBTB2, both of which are chromosome condensation regulator-like guanine nucleotide exchange factors. They contain an RCC1 repeat, a BTB domain, and a BACK domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 114 HSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPLINPVAFGALLQYLYTGRLD------IGVEHVSD 187
Cdd:cd18298    12 TSDLKFRVDGKYIYVHKAILKIRCEYFRSMFQSHWNEDDKNVIEIDQYSYPVYYAFLRYLYTDQVDlppedaIGLLDLAN 91

                          90
                  ....*....|..
gi 2289442709 188 C---ERLAKQCQ 196
Cdd:cd18298    92 SyceERLKKLCE 103

Ankyrin repeat [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709   6 LFASCRKGDVGRVRYLLEqRDVEVNVRDKWDSTPLYYACLCGHEELVRYLLANGARCEANTFDGERCLYGALSDPIRRAL 85
Cdd:COG0666   157 LHLAAANGNLEIVKLLLE-AGADVNARDNDGETPLHLAAENGHLEIVKLLLEAGADVNAKDNDGKTALDLAAENGNLEIV 235

                          90       100       110
                  ....*....|....*....|....*....|...
gi 2289442709  86 RDYKQVTASCRRRDYYDDFLQRLLEQGIHSDVV 118
Cdd:COG0666   236 KLLLEAGADLNAKDKDGLTALLLAAAAGAALIV 268

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        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 105 LQRLLEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKG---KSVVVLRHPLINPVAFGALLQYLYTGRLDIG 181
Cdd:cd18292     8 IAQLYNNEELSDIVLRVGGKVFHAHRLILAKSSDVFRVMLSNDWWSeskQSEIELVEDPECAAVFEKFLRYLYTGQISVN 87

                          90
                  ....*....|....*....
gi 2289442709 182 VEHVSDCERLAKQCQLWDL 200
Cdd:cd18292    88 LETALPLLMLADKYNVTDL 106

first BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Rho-related BTB domain-containing proteins (RhoBTB); RhoBTB proteins constitute a subfamily of atypical members within the Rho family of small guanosine triphosphatases (GTPases), which is characterized by containing a GTPase domain (in most cases, non-functional) followed by a proline-rich region, tandem BTB domains, and a conserved C-terminal region. In vertebrates, the RhoBTB subfamily consists of 3 isoforms: RhoBTB1, RhoBTB2, and RhoBTB3. Orthologs are present in several other eukaryotes, such as Drosophila and Dictyostelium, but have been lost in plants and fungi. This model corresponds to the first BTB domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 105 LQRLLEQGIHSDVVFVV-HGKPFRAHRCILGARSTYFANMLDTKwkgksVVVLRHPLINPVAFGALLQYLYTGRLDIgve 183
Cdd:cd18299     3 LRNLLHSPSCADVVFILqGGVRIFAHRIVLAAASSVFADLFLMM-----TVVTLDSDITPEAFRRVLEFLYTGVLDE--- 74

                          90       100       110
                  ....*....|....*....|....*....|
gi 2289442709 184 hvsDCERLAKQCQLWDLLD--DLEAKCEKV 211
Cdd:cd18299    75 ---NEDDLKELKDAAELLElfDLVMMCTNV 101

BTB (Broad-Complex, Tramtrack and Bric a brac) /POZ (poxvirus and zinc finger) domain found in Dictyostelium discoideum trishanku and similar proteins; Trishanku is a novel regulator required for normal morphogenesis and cell-type stability in Dictyostelium discoideum. It contains a BTB domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 269 SSCPDICFRVADSSFLCYKAFFCGRSDYFRALLDDHFQESEEPAasgdppvVTLHDISPDIFIHVLYYVYSDHTELVERE 348
Cdd:cd18314     4 SEFSDVVLCVGDRKFFAHRIVLCARSPVFRSMLTGSMIESNLKE-------VTLEDVEPEIFETVLKYMYTGQVTLSEEN 76

                  ..
gi 2289442709 349 DF 350
Cdd:cd18314    77 VL 78

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in intracisternal A particle-promoted polypeptide (IPP); IPP, also called Kelch-like protein 27 (KLHL27) or actin-binding protein IPP, is an actin-binding protein that may play a role in organizing the actin cytoskeleton. 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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 105 LQRLLEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPLINPVAFGALLQYLYTGRLDIGVEH 184
Cdd:cd18256    11 LNKLRGQHEFCDVQLQVGMELFSVHRLVLAASSPYFAALFAGGMSESSKDVVQIHGVEPDIFHILLDFIYTGVVEVTVSN 90

                          90
                  ....*....|....*...
gi 2289442709 185 VSDCERLAKQCQLWDLLD 202
Cdd:cd18256    91 VQELLVAADMLQLTEVVE 108

BTB (Broad-Complex, Tramtrack and Bric a brac) /POZ (poxvirus and zinc finger) domain found in plant regulatory proteins, NPR1-4, and similar proteins; NPR1 and NPR2 are essential for pathogenicity and the utilization of many nitrogen sources. NPR1 is also called nitrogen pathogenicity regulation protein NPR1, non-inducible immunity protein 1 (Nim1), nonexpresser of PR genes 1, or salicylic acid insensitive 1 (Sai1). It acts as a transcription coactivator that plays dual roles in regulating plant immunity. NPR3 and NPR4 are involved in negative regulation of defense responses against pathogens in plant. NPR proteins contain a BTB domain, DUF3420, ankyrin (ANK) repeats, and a conserved C-terminal domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 102 DDFLQRLLE-QGIHSDVVFVV-HGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPLINPV--------AFGALLQ 171
Cdd:cd18310     5 SDLENLLDSpDLFYSDAEIIVeGGRPVPVHRCILAARSPFFRDIFASAKAEGANTKPKLELRELIpggivgydAFMLVLS 84

                          90
                  ....*....|....*..
gi 2289442709 172 YLYTGRLDIGVEHVSDC 188
Cdd:cd18310    85 YLYSGRLRLVPKEGSAC 101

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 22 (ZBTB22); ZBTB22, also called protein BING1 or zinc finger protein 297, may be involved in transcriptional regulation. Its gene, together with BING 3-5, TAPASIN, DAXX, RGL2, and HKE2, form a dense cluster at the centromeric end of the major histocompatibility complex class I region. ZBTB22 contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 105 LQRLLEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLdtKWKGKSVVVLRHpLINPVAFGALLQYLYTGRLDIGVEH 184
Cdd:cd18210    12 LNQQRMEGKLCDISIHVQGRVFRAHRAVLAASSPYFHDQV--LLKNMSSISLPG-VMDPGAFESVLASAYTGKLTMLADE 88

                          90       100
                  ....*....|....*....|....
gi 2289442709 185 VSDCERLAKQCQLWDLLDdleaKC 208
Cdd:cd18210    89 IVNYLTVGSVLQMWHIVD----KC 108

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in BTB and CNC homolog 2 (BACH2); BACH2, also called BTB-basic leucine zipper transcription factor 2, belongs to the cap 'n' collar (CNC) and basic leucine zipper (bZIP) factor family. BACH2 is a lymphoid-specific transcription factor with a prominent role in B-cell development. It is transcriptionally regulated by the BCR/ABL oncogene. It represses the anti-apoptotic factor heme oxygenase-1 (HO-1). It is also a potent general repressor of effector differentiation in naive T cells. Moreover, BACH2 is required for pulmonary surfactant homeostasis and alveolar macrophage function. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 110 EQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPlINPVAFGALLQYLYTGRLDIGVEHVSDCE 189
Cdd:cd18278    27 KQDILCDVTLIVEGKEFRAHRAVLAACSEYFLQALVGQTENDLVVSLPEE-VTARGFGPLLQFAYTAKLLLSRENIQEVI 105

                          90
                  ....*....|...
gi 2289442709 190 RLAKQCQLWDLLD 202
Cdd:cd18278   106 RCAEFLRMHNLED 118

BTB (Broad-Complex, Tramtrack and Bric a brac) /POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster proteins bric-a-brac 1 (BAB1), bric-a-brac 2 (BAB2), modifier of mdg4 (doom), and similar proteins; BAB1 and BAB2 probably act as transcriptional regulators that are required for specification of the tarsal segment and are involved in antenna development. Doom is a product of the Drosophila mod(mdg4) gene. It induces apoptosis and binds to baculovirus inhibitor-of-apoptosis proteins. This subfamily also includes Drosophila melanogaster sex determination protein fruitless (FRU), protein jim lovell (LOV), zinc finger protein chinmo, transcription factor GAGA, transcription factor Ken, and longitudinals lacking proteins (LOLA). FRU probably acts as a transcriptional regulator that plays a role in male courtship behavior and sexual orientation, and enhances male-specific expression of takeout in brain-associated fat body. LOV, also called tyrosine kinase-related (TKR), has a regulatory role during midline cell development. Chinmo is a functional effector of the JAK/STAT pathway that regulates eye development, tumor formation, and stem cell self-renewal in Drosophila. GAGA is a transcriptional activator that functions by regulating chromatin structure. Ken, also termed protein Ken and Barbie, is a transcription factor required for Terminalia development. LOLA proteins are putative transcription factors required for axon growth and guidance in the central and peripheral nervous systems. Proteins in this subfamily contain a BTB domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 114 HSDVVFVVHGKPFRAHRCILGARSTYFANMLdTKWKGKSVVVLRHPLINPVAFGALLQYLYTGRLDIGVEHVSDCERLAK 193
Cdd:cd18315     1 LVDVTLACEGGSLKAHKLVLAAASPYFAALL-KETPPDEHPVIILPDVPYSELKALLDFIYTGEVNVSQEQLESLLKLAE 79

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Influenza virus NS1A-binding protein (NS1-BP); NS1-BP is also called NS1-binding protein, aryl hydrocarbon receptor-associated protein 3 (ARA3), or IVNS1ABP. It is a novel protein that interacts with the influenza A virus nonstructural NS1 protein, which is relocalized in the nuclei of infected cells. It plays a role in cell division and in the dynamic organization of the actin skeleton as a stabilizer of actin filaments by association with F-actin through its kelch repeats. It also interacts with alpha-enolase/MBP-1 and is involved in c-Myc gene transcriptional control. NS1-BP contains BTB and BACK domains at the N-terminal region and kelch repeats at the C-terminal region. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 105 LQRLLEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPLINPVAFGALLQYLYTGRLDIGVEH 184
Cdd:cd18306     9 LNALRKNRQFCDVILQVGGHEIPAHRAVLACASPYLFELFSSDSDGESILTVKLDGLDPDAVEVLVNYAYTSRLEVPADL 88

                          90
                  ....*....|
gi 2289442709 185 VSDCERLAKQ 194
Cdd:cd18306    89 VKSVYSAAKK 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in B-cell lymphoma 6 proteins, BCL-6 and BCL-6B; This family includes B-cell lymphoma 6 proteins, BCL-6 and BCL-6B. BCL-6 is a transcriptional repressor mainly required for germinal center (GC) formation and antibody affinity maturation, which have different mechanisms of action specific to the lineage and biological functions. BCL-6B is a sequence-specific transcriptional repressor in association with BCL-6. It may function in a narrow stage or be related to some events in the early B-cell development. Family members contain a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2289442709 105 LQRLLEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPLINPVAFGALLQYLYTGRL 178
Cdd:cd18215    10 LNRLRSRDILTDVVLVVGREQFRAHKTVLMACSGLFYSIFTDQLKNNVSVINLDPEIEPEGFRILLDFMYTSRL 83

Ankyrin repeats (3 copies);

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 2289442709   6 LFASCRKGDVGRVRYLLEQrDVEVNVRDKWDSTPLYYACLCGHEELVRYLLAN 58
Cdd:pfam12796   1 LHLAAKNGNLELVKLLLEN-GADANLQDKNGRTALHLAAKNGHLEIVKLLLEH 52

second BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Rho-related BTB domain-containing proteins (RhoBTB); RhoBTB proteins constitute a subfamily of atypical members within the Rho family of small guanosine triphosphatases (GTPases), which is characterized by containing a GTPase domain (in most cases, non-functional) followed by a proline-rich region, a tandem of 2 BTB domains, and a conserved C-terminal region. In humans, the RhoBTB subfamily consists of 3 isoforms: RhoBTB1, RhoBTB2, and RhoBTB3. Orthologs are present in several other eukaryotes, such as Drosophila and Dictyostelium, but have been lost in plants and fungi. This model corresponds to the second BTB domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2289442709 108 LLEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPLINPVAFGALLQYLYTGRLDI 180
Cdd:cd18300     3 FLNKGLFSDVTFIVEDGTIPAHKALLVARCDVMAAMFGGNFRESSAKEVELPGVSKETFLALLEYLYTDQAPI 75

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch repeat and BTB domain-containing protein 4 (KBTBD4); KBTBD4, also called BTB and kelch domain-containing protein 4 (BKLHD4), is a BTB-BACK-Kelch domain protein belonging to a large family of cullin-RING ubiquitin ligase adaptors that facilitate the ubiquitination of target substrates. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 109 LEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPLINPVAFGALLQYLYTGRLDIGVEHVSDC 188
Cdd:cd18272    27 LEDGLFADVTISVEGKEFQLHRLVLSAQSCFFRSMFTSNLKEARNRVIELKDVSESVFQLLVDYIYHGTVKLRVEELQET 106

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|
gi 2289442709 189 ERLAKQCQLWDLLddleakcEKVSEFVAS--KPGTCVKVL 226
Cdd:cd18272   107 YEVADMYQLTALF-------EECSRFLARtvQVRNCLQVM 139

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 24 (KLHL24); KLHL24, also called kainate receptor-interacting protein for GluR6 (KRIP6) or protein DRE1, is necessary to maintain the balance between intermediate filament stability and degradation, a process that is essential for skin integrity. KLHL24 is a component of a BCR (BTB-CUL3-RBX1) E3 ubiquitin ligase complex that mediates ubiquitination of KRT14 and controls its levels during keratinocyte differentiation. 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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 105 LQRLLEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPLINPVAFGALLQYLYTGRLDIGVEH 184
Cdd:cd18253     9 FNEFRDSRLFTDVIICVEGREFPCHRAILSACSSYFRAMFCNDHRESREMLVEINGILAEAMDCFLQYVYTGKVKITTEN 88

                  .
gi 2289442709 185 V 185
Cdd:cd18253    89 V 89

first BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in BTB/POZ domain-containing protein 7 (BTBD7); BTBD7 is a crucial regulator that is essential for region-specific epithelial cell dynamics and branching morphogenesis. It has been implicated in various cancers. BTBD7 contains two BTB domains. This model corresponds to the first domain. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 115 SDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVV--LRHPLINPVAFGALLQYLYTGRLDIGVEHVSDCE--- 189
Cdd:cd18283     3 TDVDLVFQGTCFPVHRAILSARCPFFRDLLSSSPGYGAEIPvdLPTAGIDVPMFSALLRYLYTGEFGSEDSRSQNLDvli 82

                  ....*.
gi 2289442709 190 RLAKQC 195
Cdd:cd18283    83 QLSEEF 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in zinc finger and BTB domain-containing protein 34 (ZBTB34); ZBTB34 acts as a transcriptional regulator. It downregulates specificity protein (Sp) transcription factors Sp1, Sp3, and Sp4 in pancreatic cancer cells. It contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2289442709 105 LQRLLEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLD-TKWKGKSVVVLRhpliNPVAFGALLQYLYTGRLDIGVE 183
Cdd:cd18220    16 LNELRLQGKLCDIIVHIQGQPFRAHKAVLAASSPYFRDHSAlSTMSGLSISVIK----NPNVFEQLLSFCYTGRMSLQLK 91

                          90       100       110
                  ....*....|....*....|....*....|
gi 2289442709 184 HVSDCERLAKQCQLWDLLDdleaKCEKVSE 213
Cdd:cd18220    92 DVVSFLTAASFLQMQCVID----KCTQILE 117

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in speckle-type POZ protein (SPOP) and similar proteins; This family includes speckle-type POZ protein (SPOP), speckle-type POZ protein-like (SPOPL), TD and POZ domain-containing proteins (TDPOZ), Drosophila melanogaster protein roadkill and similar proteins. Both, SPOP and SPOPL, serve as adaptors of cullin-RING-based BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complexes that mediate the ubiquitination and proteasomal degradation of target proteins. TDPOZ is a family of bipartite animal and plant proteins that contain a tumor necrosis factor receptor-associated factor (TRAF) domain (TD) and a POZ/BTB domains. TDPOZ proteins may be nuclear scaffold proteins probably involved in transcription regulation in early development and other cellular processes. Drosophila melanogaster protein roadkill, also called Hh-induced MATH and BTB domain-containing protein (HIB), is a hedgehog-induced BTB protein that modulates hedgehog signaling by degrading Ci/Gli transcription factor. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2289442709 103 DFLQRLLEQGIHSDVVFVVHGKPFRAHRCILGARSTYFANMLDTKWKGKSVVVLRHPLINPVAFGALLQYLYTGR 177
Cdd:cd18279     7 EDLGNLWENSRFTDCCLCVGGQEFQAHKAILAARSPVFSAMFEHEMEESKKNRVEINDVDPEVFKEMMRFIYTGK 81