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Solution structure of conserved AGNN tetraloops: insights into Rnt1p RNA processing
Author(s) -
Lebars Isabelle,
Lamontagne Bruno,
Yoshizawa Satoko,
Elela Sherif Abou,
Fourmy Dominique
Publication year - 2001
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/20.24.7250
Subject(s) - biology , rna , nucleic acid structure , computational biology , rna processing , conserved sequence , genetics , base sequence , evolutionary biology , dna , gene
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.