title: Structural and biochemical characterization of the yeast exosome component Rrp40.
abstract: The exosome is a protein complex that is important in both degradation and 3'-processing of eukaryotic RNAs. We present the crystal structure of the Rrp40 exosome subunit from Saccharomyces cerevisiae at a resolution of 2.2 A. The structure comprises an S1 domain and an unusual KH (K homology) domain. Close packing of the S1 and KH domains is stabilized by a GxNG sequence, which is uniquely conserved in exosome KH domains. Nuclear magnetic resonance data reveal the presence of a manganese-binding site at the interface of the two domains. Isothermal titration calorimetry shows that Rrp40 and archaeal Rrp4 alone have very low intrinsic affinity for RNA. The affinity of an archaeal core exosome for RNA is significantly increased in the presence of the S1-KH subunit Rrp4, indicating that multiple subunits might contribute to cooperative binding of RNA substrates by the exosome.
authors.affiliation: European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117 Heidelberg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Oddone
authors.forename: Esben
authors.initials: E
authors.lastname: Lorentzen
authors.forename: Jerome
authors.initials: J
authors.lastname: Basquin
authors.forename: Alexander
authors.initials: A
authors.lastname: Gasch
authors.forename: Vladimir
authors.initials: V
authors.lastname: Rybin
authors.forename: Elena
authors.initials: E
authors.lastname: Conti
authors.forename: Michael
authors.initials: M
authors.lastname: Sattler
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D005095:Exoribonucleases / Q000737:chemistry* / Q000235:genetics; D063326:Exosome Multienzyme Ribonuclease Complex; D008345:Manganese / Q000737:chemistry; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics; D012313:RNA / Q000737:chemistry; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics; D016415:Sequence Alignment; D017384:Sequence Deletion
chemical_list: D021122:Protein Subunits; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D008345:Manganese; D012313:RNA; D005095:Exoribonucleases; D063326:Exosome Multienzyme Ribonuclease Complex; C518474:Rrp40 protein, S cerevisiae