RNA recognition motif 2 (RRM2) found in RNA-binding protein 40 (RBM40) and similar proteins
This subfamily corresponds to the RRM2 of RBM40 and the RRM of RBM41. 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 RNA recognition motifs (RRMs), also known as RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), 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. RBM41 contains only one RRM. Its biological function remains unclear.