RNA recognition motif 1 (RRM1) found in RNA-binding protein 40 (RBM40) and similar proteins
This subfamily corresponds to the RRM1 of RBM40, also known as RNA-binding region-containing protein 3 (RNPC3) or U11/U12 small nuclear ribonucleoprotein 65 kDa protein (U11/U12-65K protein), It serves as a bridging factor between the U11 and U12 snRNPs. It contains two repeats of RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), 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.