title: Reconstitution, activities, and structure of the eukaryotic RNA exosome.
abstract: The RNA exosome is a multisubunit 3' to 5' exoribonuclease complex that participates in degradation and processing of cellular RNA. To determine the activities and structure of the eukaryotic exosome, we report the reconstitution of 9-subunit exosomes from yeast and human and reconstitution of 10- and 11-subunit exosomes from yeast. Comparative biochemical analysis between purified subunits and reconstituted exosomes using AU-rich, polyadenylated (poly[A]), generic, and structured RNA substrates reveals processive phosphorolytic activities for human Rrp41/Rrp45 and the 9-subunit human exosome, processive hydrolytic activities for yeast Rrp44 and the yeast 10-subunit exosome, distributive hydrolytic activities for Rrp6, and processive and distributive hydrolytic activities for the yeast 11-subunit exosome. To elucidate the architecture of a eukaryotic exosome, its conserved surfaces, and the structural basis for RNA decay, we report the X-ray structure determination for the 286 kDa nine-subunit human exosome at 3.35 A.
authors.affiliation: Structural Biology Program, Sloan-Kettering Institute, New York, NY 10021, USA.
authors.forename: Quansheng
authors.initials: Q
authors.lastname: Liu
authors.forename: Jaclyn C
authors.initials: JC
authors.lastname: Greimann
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Lima
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D018076:DNA, Complementary; D005095:Exoribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010920:Placenta / Q000737:chemistry; D011247:Pregnancy; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism; D020871:RNA Stability; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D019843:Archaeal Proteins; D018076:DNA, Complementary; D029701:Saccharomyces cerevisiae Proteins; D012313:RNA; D005095:Exoribonucleases