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Rnt1p, the yeast orthologue of RNase III, cleaves rRNAs, snRNAs and snoRNAs at a stem capped with conserved AGNN tetraloop. Here we show that 9 bp long stems ending with AGAA or AGUC tetraloops bind to Rnt1p and direct specific but sequence-independent RNA cleavage when provided with stems longer than 13 bp. The solution structures of these two tetraloops reveal a common fold for the terminal loop stabilized by non-canonical A-A or A-C pairs and extensive base stacking. The conserved nucleotides are stacked at the 5' side of the loop, exposing their Watson-Crick and Hoogsteen faces for recognition by Rnt1p. These results indicate that yeast RNase III recognizes the fold of a conserved single-stranded tetraloop to direct specific dsRNA cleavage.
Solution structure of conserved AGNN tetraloops: insights into Rnt1p RNA processing.,Lebars I, Lamontagne B, Yoshizawa S, Aboul-Elela S, Fourmy D EMBO J. 2001 Dec 17;20(24):7250-8. PMID:11743001[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑ Lebars I, Lamontagne B, Yoshizawa S, Aboul-Elela S, Fourmy D. Solution structure of conserved AGNN tetraloops: insights into Rnt1p RNA processing. EMBO J. 2001 Dec 17;20(24):7250-8. PMID:11743001 doi:10.1093/emboj/20.24.7250
