InterPro domain: IPR043136

The B30.2 domain was first identified as a protein domain encoded by an exon (named B30-2) in the Homo sapiens class I major histocompatibility complex region [ 1 ], whereas the SPRY domain was first identified in a Dictyostelium discoideum kinase splA and mammalian calcium-release channels ryanodine receptors [ 2 ]. B30.2 domain consists of PRY and SPRY subdomains. The SPRY domains (after SPla and the RYanodine Receptor) are shorter at the N terminus than the B30.2 domains. The ~200-residue B30.2/SPRY (for B30.2 and/or SPRY) domain is present in a large number of proteins with diverse individual functions in different biological processes. The B30.2/SPRY domain in these proteins is likely to function through protein-protein interaction [ 3 ].The N-terminal ~60 residues of B30.2/SPRY domains are poorly conserved and, as a consequence, a new domain name PRY was coined for a group of similar sequence segments N-terminal to the SPRY domains [ 4 ]. The B30.2/SPRY domain contains three highly conserved motifs (LDP, WEVE and LDYE) [ 4 ]. The B30.2/SPRY domain adopts a highly distorted, compact beta-sandwich fold with two additional short beta helices at the N terminus. The beta sandwich of the B30.2/SPRY domain consists of two layers of beta sheets: sheet A composed of eight strands and sheet B composed of seven strands. All the beta strands are in antiparallel arrangement [ 5 ]. The 5th beta-strand corresponding to WEVE motif [ 5 ]. Both the N- and C-terminal ends of the B30.2/SPRY domains in general are close to each other [ 6 ].

This superfamily also matches diverse E3 ubiquitin-protein ligases. This protein is involved in the apoptosis process [ 6 , 7 ].

1. Evolutionary study of multigenic families mapping close to the human MHC class I region. J. Mol. Evol. 37, 600-12
2. SPRY domains in ryanodine receptors (Ca(2+)-release channels). Trends Biochem. Sci. 22, 193-4
3. Structural and functional insights into the B30.2/SPRY domain. EMBO J. 25, 1353-63
4. B30.2-like domain proteins: a growing family. Biochem. Biophys. Res. Commun. 235, 162-5
5. Protein fold analysis of the B30.2-like domain. Proteins 35, 235-49
6. TRIM39 is a MOAP-1-binding protein that stabilizes MOAP-1 through inhibition of its poly-ubiquitination process. Exp. Cell Res. 315, 1313-25
7. The Trim39 ubiquitin ligase inhibits APC/CCdh1-mediated degradation of the Bax activator MOAP-1. J. Cell Biol. 197, 361-7