title: Crystal structures of Lsm3, Lsm4 and Lsm5/6/7 from Schizosaccharomyces pombe.
abstract: Sm-like (Lsm) proteins are ubiquitous and function in many aspects of RNA metabolism, including pre-mRNA splicing, nuclear RNA processing, mRNA decay and miRNA biogenesis. Here three crystal structures including Lsm3, Lsm4 and Lsm5/6/7 sub-complex from S. pombe are reported. These structures show that all the five individual Lsm subunits share a conserved Sm fold, and Lsm3, Lsm4, and Lsm5/6/7 form a heptamer, a trimer and a hexamer within the crystal lattice, respectively. Analytical ultracentrifugation indicates that Lsm3 and Lsm5/6/7 sub-complex exist in solution as a heptamer and a hexamer, respectively while Lsm4 undergoes a dynamic equilibrium between monomer and trimer in solution. RNA binding assays show that Lsm2/3 and Lsm5/6/7 bind to oligo(U) whereas no RNA binding is observed for Lsm3 and Lsm4. Analysis of the inter-subunit interactions in Lsm5/6/7 reveals the organization order among Lsm5, Lsm6 and Lsm7.
authors.affiliation: Institute of Molecular and Cell Biology, Singapore, Singapore.
authors.forename: Donghui
authors.initials: D
authors.lastname: Wu
authors.forename: Shimin
authors.initials: S
authors.lastname: Jiang
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Bowler
authors.forename: Haiwei
authors.initials: H
authors.lastname: Song
mesh_terms: D018360:Crystallography, X-Ray; D008958:Models, Molecular; D011487:Protein Conformation; D012568:Schizosaccharomyces / Q000737:chemistry*