title: The structure and selectivity of the SR protein SRSF2 RRM domain with RNA.
abstract: SRSF2 is a prototypical SR protein which plays important roles in the alternative splicing of pre-mRNA. It has been shown to be involved in regulatory pathways for maintaining genomic stability and play important roles in regulating key receptors in the heart. We report here the solution structure of the RNA recognition motifs (RRM) domain of free human SRSF2 (residues 9-101). Compared with other members of the SR protein family, SRSF2 structure has a longer L3 loop region. The conserved aromatic residue in the RNP2 motif is absent in SRSF2. Calorimetric titration shows that the RNA sequence 5'AGCAGAGUA3' binds SRSF2 with a K(d) of 61 ± 1 nM and a 1:1 stoichiometry. NMR and mutagenesis experiments reveal that for SFSF2, the canonical β1 and β3 interactions are themselves not sufficient for effective RNA binding; the additional loop L3 is crucial for RNA complex formation. A comparison is made between the structures of SRSF2-RNA complex with other known RNA complexes of SR proteins. We conclude that interactions involving the L3 loop, N- and C-termini of the RRM domain are collectively important for determining selectivity between the protein and RNA.
authors.affiliation: NMR Centre for Structural Biology, University of Liverpool, Institute of Integrative Biology, Crown Street, Liverpool L69 7ZB, UK.
authors.forename: Marie M
authors.initials: MM
authors.lastname: Phelan
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Goult
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Clayton
authors.forename: Guillaume M
authors.initials: GM
authors.lastname: Hautbergue
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Wilson
authors.forename: Lu-Yun
authors.initials: LY
authors.lastname: Lian
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002151:Calorimetry; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D019906:Nuclear Magnetic Resonance, Biomolecular; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012313:RNA / Q000737:chemistry* / Q000378:metabolism; D012261:Ribonucleoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D000068103:Serine-Arginine Splicing Factors
chemical_list: D009687:Nuclear Proteins; D012261:Ribonucleoproteins; C073288:SRSF2 protein, human; D000068103:Serine-Arginine Splicing Factors; D012313:RNA