title: New insights into the mechanism of RNA degradation by ribonuclease II: identification of the residue responsible for setting the RNase II end product.
abstract: RNase II is a key exoribonuclease involved in the maturation, turnover, and quality control of RNA. RNase II homologues are components of the exosome, a complex of exoribonucleases. The structure of RNase II unraveled crucial aspects of the mechanism of RNA degradation. Here we show that mutations in highly conserved residues at the active site affect the activity of the enzyme. Moreover, we have identified the residue that is responsible for setting the end product of RNase II. In addition, we present for the first time the models of two members of the RNase II family, RNase R from Escherichia coli and human Rrp44, also called Dis3. Our findings improve the present model for RNA degradation by the RNase II family of enzymes.
authors.affiliation: Instituto de Tecnologia Química e Biológica/Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Barbas
authors.forename: Rute G
authors.initials: RG
authors.lastname: Matos
authors.forename: Mónica
authors.initials: M
authors.lastname: Amblar
authors.forename: Eduardo
authors.initials: E
authors.lastname: López-Viñas
authors.forename: Paulino
authors.initials: P
authors.lastname: Gomez-Puertas
authors.forename: Cecília M
authors.initials: CM
authors.lastname: Arraiano
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005095:Exoribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism*
chemical_list: D012313:RNA; D005095:Exoribonucleases; C022535:exoribonuclease II