title: Crystal structure of Cwc2 reveals a novel architecture of a multipartite RNA-binding protein.
abstract: The yeast splicing factor Cwc2 contacts several catalytically important RNA elements in the active spliceosome, suggesting that Cwc2 is involved in determining their spatial arrangement at the spliceosome's catalytic centre. We have determined the crystal structure of the Cwc2 functional core, revealing how a previously uncharacterized Torus domain, an RNA recognition motif (RRM) and a zinc finger (ZnF) are tightly integrated in a compact folding unit. The ZnF plays a pivotal role in the architecture of the whole assembly. UV-induced crosslinking of Cwc2-U6 snRNA allowed the identification by mass spectrometry of six RNA-contacting sites: four in or close to the RRM domain, one in the ZnF and one on a protruding element connecting the Torus and RRM domains. The three distinct regions contacting RNA are connected by a contiguous and conserved positively charged surface, suggesting an expanded interface for RNA accommodation. Cwc2 mutations confirmed that the connector element plays a crucial role in splicing. We conclude that Cwc2 acts as a multipartite RNA-binding platform to bring RNA elements of the spliceosome's catalytic centre into an active conformation.
authors.affiliation: Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Schmitzová
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rasche
authors.forename: Olexander
authors.initials: O
authors.lastname: Dybkov
authors.forename: Katharina
authors.initials: K
authors.lastname: Kramer
authors.forename: Patrizia
authors.initials: P
authors.lastname: Fabrizio
authors.forename: Henning
authors.initials: H
authors.lastname: Urlaub
authors.forename: Reinhard
authors.initials: R
authors.lastname: Lührmann
authors.forename: Vladimir
authors.initials: V
authors.lastname: Pena
mesh_terms: D001483:Base Sequence; D008969:Molecular Sequence Data; D059372:Nucleotide Motifs; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D012322:RNA Precursors / Q000235:genetics; D012326:RNA Splicing; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics; D016335:Zinc Fingers
chemical_list: C543031:Cwc2 protein, S cerevisiae; D012322:RNA Precursors; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins