Structural basis for the recognition ofspliceosomal SmN B B proteins by theRBM5 OCRE domain in splicing regulation
Mourao, A., Bonnal, S., Komal, S., Warner, L., Bordonne, R., Valcarcel, J., Sattler, M.(2016) Elife 5: 1-25
- PubMed: 27894420 
- DOI: https://doi.org/10.7554/eLife.14707
- Primary Citation of Related Structures:  
5MF9, 5MFY - PubMed Abstract: 
The multi-domain splicing factor RBM5 regulates the balance between antagonistic isoforms of the apoptosis-control genes FAS/CD95 , Caspase-2 and AID . An OCRE (OCtamer REpeat of aromatic residues) domain found in RBM5 is important for alternative splicing regulation and mediates interactions with components of the U4/U6.U5 tri-snRNP. We show that the RBM5 OCRE domain adopts a unique β-sheet fold. NMR and biochemical experiments demonstrate that the OCRE domain directly binds to the proline-rich C-terminal tail of the essential snRNP core proteins SmN/B/B'. The NMR structure of an OCRE-SmN peptide complex reveals a specific recognition of poly-proline helical motifs in SmN/B/B'. Mutation of conserved aromatic residues impairs binding to the Sm proteins in vitro and compromises RBM5-mediated alternative splicing regulation of FAS/CD95. Thus, RBM5 OCRE represents a poly-proline recognition domain that mediates critical interactions with the C-terminal tail of the spliceosomal SmN/B/B' proteins in FAS/CD95 alternative splicing regulation.
Organizational Affiliation: 
Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany.