Occluded RNA-recognition motif (IPR031766)

Short name: RRM_occluded

Overlapping homologous superfamilies


Domain relationships


This is an unusual, usually C-terminal, RNA-recognition motif found in fungi. In yeast it is the fourth RRM domain on the essential splicing factor Prp24. Structurally, it has a non-canonical RRM fold with the expected beta-aloha-beta-beta-alpha-beta RRM-fold is flanked by N- and C-terminal alpha-helices. These two additional flanking alpha-helices occlude the beta-sheet face. The electropositive surface thereby presented is an alternative RNA-binding surface that allows both binding and unwinding of the U6 small nuclear RNA's internal stem loop, at least in vitro [PMID: 21653550].

Prp24 is an RNA-binding protein with four well conserved RNA recognition motifs (RRMs). It facilitates U6 RNA base-pairing with U4 RNA during spliceosome assembly [PMID: 21653550]. Prp24 specifically binds free U6 RNA primarily with RRM 1 and 2 and facilitates pairing of U6 RNA bases with U4 RNA bases [PMID: 20181740, PMID: 15811912].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.