title: The SRSF1 linker induces semi-conservative ESE binding by cooperating with the RRMs.
abstract: SR proteins promote spliceosome formation by recognizing exonic splicing enhancers (ESEs) during pre-mRNA splicing. Each SR protein binds diverse ESEs using strategies that are yet to be elucidated. Here, we show that the RNA-binding domain (RBD) of SRSF1 optimally binds to decameric purine rich ESE sequences although locations of purines are not stringently specified. The presence of uracils either within or outside of the recognition site is detrimental for binding with SRSF1. The entire RBD, comprised of two RRMs and a glycine-rich linker, is essential for ESE binding. Mutation within each segment reduced or nearly abolished binding, suggesting that these segments mediate cooperative binding. The linker plays a decisive role in organizing ESE binding. The flanking basic regions of the linker appear to communicate with each other in bringing the two RRMs close together to form the complex with RNA. Our study thus suggests semi-conservative adaptable interaction between ESE and SRSF1, and such binding mode is not only essential for the recognition of plethora of physiological ESE sequences but may also be essential for the interaction with various factors during the spliceosome assembly.
authors.affiliation: Department of Chemistry & Biochemistry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA.
authors.forename: Suhyung
authors.initials: S
authors.lastname: Cho
authors.forename: Amy
authors.initials: A
authors.lastname: Hoang
authors.forename: Sutapa
authors.initials: S
authors.lastname: Chakrabarti
authors.forename: Nhat
authors.initials: N
authors.lastname: Huynh
authors.forename: De-Bin
authors.initials: DB
authors.lastname: Huang
authors.forename: Gourisankar
authors.initials: G
authors.lastname: Ghosh
mesh_terms: D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D012326:RNA Splicing; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D038621:Regulatory Sequences, Ribonucleic Acid; D000068103:Serine-Arginine Splicing Factors; D014498:Uracil / Q000032:analysis
chemical_list: D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D038621:Regulatory Sequences, Ribonucleic Acid; D000068103:Serine-Arginine Splicing Factors; D014498:Uracil; D012313:RNA