title: Exonucleolytic degradation of double-stranded RNA by an activity in Xenopus laevis germinal vesicles.
abstract: We have identified, in extracts from Xenopus laevis germinal vesicles, a 5' exonuclease activity that cleaves double-stranded RNA (dsRNA). Features of the 5' ends of dsRNAs determine whether the strands are symmetrically or asymmetrically degraded. The activity hydrolyzes in the 5' to 3' direction, releasing 5'-mononucleotides processively, favoring strands with 5'-monophosphate termini; molecules with capped ends are resistant to digestion. Because of its ability to processively digest dsRNA to mononucleotides, we have named the exonuclease Chipper, which could cooperate or compete with Dicer (an endonuclease that produces molecules with a 5'-phosphate) in the processing of dsRNA.
authors.affiliation: Istituto di Biologia Cellulare, Consiglio Nazionale delle Ricerche, Campus A. Buzzati-Traverso,Via Ramarini, 32, 00016 Monterotondo Scalo, Rome, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Fruscoloni
authors.forename: Michela
authors.initials: M
authors.lastname: Zamboni
authors.forename: M Irene
authors.initials: MI
authors.lastname: Baldi
authors.forename: Glauco P
authors.initials: GP
authors.lastname: Tocchini-Valentini
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D005092:Exonucleases / Q000378:metabolism*; D006868:Hydrolysis; D009690:Nucleic Acid Conformation; D012330:RNA, Double-Stranded / Q000737:chemistry / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D017931:DNA Primers; D012330:RNA, Double-Stranded; D005092:Exonucleases