| Primary Identifier | IPR003879 | Type | Domain |
| Short Name | Butyrophylin_SPRY |
| description | Several proteins that contain RING fingers also contain a well-conserved40-residue cysteine-rich domain termed a B-box zinc finger. Often, one or two copies of the B-box are associated with a coiled coil domain in additionto the ring finger, forming a tripartite motif. The tripartite motif is found in transcription factors, ribonucleoproteins and proto-oncoproteins,but no function has yet been ascribed to the domain [].The solution structure of the B-box motif has been determined by NMR. The protein is a monomer, with 2 β-strands, 2 helical turns and 3extended loop regions packed in a novel topology []. Of 7 potential zincligands, only 4 are used, binding a single zinc atom in a C2-H2 tetrahedral arrangement. The B-box structure differs in tertiary fold from allother known zinc-binding motifs.A group of proteins that contain the B-box motif also host a well conserveddomain of unknown function. Proteins that include this domain are,e.g.: butyrophilin, the RET finger protein, the 52kDa Ro protein and theXenopus nuclear factor protein. The C-terminal portion of this region hasbeen termed the SPRY domain (after SPla and the RYanodine Receptor) []. |
