InterPro domain: IPR034147

This entry represents the RNA recognition motif 1 (RRM1) of RBM40 (also known as U11/U12-65K). RBM40 serves as a bridging factor between the U11 and U12 snRNPs [ 1 ]. It contains two repeats of an RNA recognition motif (RRM), connected by a linker that includes a proline-rich region. It binds to the U11-associated 59K protein via its RRM1 and employs the RRM2 to bind hairpin III of the U12 small nuclear RNA (snRNA). The proline-rich region might be involved in protein-protein interactions [ 2 ].

1. The U11/U12 snRNP 65K protein acts as a molecular bridge, binding the U12 snRNA and U11-59K protein. EMBO J. 24, 3057-69
2. Functional stabilization of an RNA recognition motif by a noncanonical N-terminal expansion. RNA 15, 1305-13