Structural highlights
FunctionRNT1_YEAST DsRNA-specific nuclease that cleaves eukaryotic pre-ribosomal RNA at the U3 snoRNP-dependent A0 site in the 5'-external transcribed spacer (ETS) and in the 3'-ETS. In vitro, cleaves synthetic 5'-ETS RNA A0 site in the absence of snoRNA or other factors. Has an essential growth function in addition to pre-rRNA processing. Publication Abstract from PubMedRibonuclease III (RNase III) enzymes are a family of double-stranded RNA (dsRNA)-specific endoribonucleases required for RNA maturation and gene regulation. Prokaryotic RNase III enzymes have been well characterized, but how eukaryotic RNase IIIs work is less clear. Here, we describe the structure of the Saccharomyces cerevisiae RNase III (Rnt1p) postcleavage complex and explain why Rnt1p binds to RNA stems capped with an NGNN tetraloop. The structure shows specific interactions between a structural motif located at the end of the Rnt1p dsRNA-binding domain (dsRBD) and the guanine nucleotide in the second position of the loop. Strikingly, structural and biochemical analyses indicate that the dsRBD and N-terminal domains (NTDs) of Rnt1p function as two rulers that measure the distance between the tetraloop and the cleavage site. These findings provide a framework for understanding eukaryotic RNase IIIs. Structure of a Eukaryotic RNase III Postcleavage Complex Reveals a Double-Ruler Mechanism for Substrate Selection.,Liang YH, Lavoie M, Comeau MA, Abou Elela S, Ji X Mol Cell. 2014 Apr 2. pii: S1097-2765(14)00211-1. doi:, 10.1016/j.molcel.2014.03.006. PMID:24703949[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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