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 [], whereas the SPRY domain was first identified in a Dictyostelium discoideum kinase splA and mammalian calcium-release channels ryanodine receptors []. 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 [].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 []. The B30.2/SPRY domain contains three highly conserved motifs (LDP, WEVE and LDYE) []. The B30.2/SPRY domain adopts a highly distorted, compact β-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 []. The 5th β-strand corresponding to WEVE motif []. Both the N- and C-terminal ends of the B30.2/SPRY domains in general are close to each other [].Tripartite motif-containing proteins (TRIMs) play a variety roles in innate immunity. TRIM14 is a noncanonical TRIM that lacks an E3 ubiquitin ligase RING domain. It is involved in type I IFN signaling in innate immunity [, , ]. This entry represents the PRY/SPRY domain of TRIM14.
