Exonucleolytic degradation of double-stranded RNA by an activity in Xenopus laevis germinal vesicles.
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.
Fruscoloni
Paolo
P
Istituto di Biologia Cellulare, Consiglio Nazionale delle Ricerche, Campus A. Buzzati-Traverso,Via Ramarini, 32, 00016 Monterotondo Scalo, Rome, Italy.
Zamboni
Michela
M
Baldi
M Irene
MI
Tocchini-Valentini
Glauco P
GP
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
D017931:DNA Primers; D012330:RNA, Double-Stranded; D005092:Exonucleases