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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 115532520   44 SPIFNVMcFGKDFEKMDLSR-EIVDEKSNDIDCFLRAVHDTSMINSSNFALVLRLSNKYQVDPVIDACQNFIIRQ 117
Cdd:pfam00651  33 SPYFKAL-FSGQESESSVSEiTLDDVSPEDFEALLEFMYTGKLISEENVDDLLAAADKLQIPSLVDKCEEFLIKS 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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 115532520   44 SPIFNVMcFGKDFEKMDLSR-EIVDEKSNDIDCFLRAVHDTSMINSSNFALVLRLSNKYQVDPVIDACQNFIIRQ 117
Cdd:pfam00651  33 SPYFKAL-FSGQESESSVSEiTLDDVSPEDFEALLEFMYTGKLISEENVDDLLAAADKLQIPSLVDKCEEFLIKS 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 115532520   44 SPIFNVMcFGKDFEKMDLSR-EIVDEKSNDIDCFLRAVHDTSMINSSNFALVLRLSNKYQVDPVIDACQNFIIRQ 117
Cdd:pfam00651  33 SPYFKAL-FSGQESESSVSEiTLDDVSPEDFEALLEFMYTGKLISEENVDDLLAAADKLQIPSLVDKCEEFLIKS 106