Frequent occurrence of the T-loop RNA folding motif in ribosomal RNAs.
RNA
; 8(9): 1112-9, 2002 Sep.
Article
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| MEDLINE
| ID: mdl-12358430
ABSTRACT
Analysis of atomic resolution structures of the rRNAs within the context of the 50S and the 30S ribosomal subunits have revealed the presence of nine examples of a recurrent structural motif, first observed in the TpsiC loop of tRNAs. The key component of this T-loop motif is a UA trans Watson-Crick/Hoogsteen base pair stacked on a Watson-Crick pair on one side. This motif is stabilized by several noncanonical hydrogen bonds, facilitating RNA-RNA as well as RNA-protein interactions. In particular, the sugar edge of the purine on the 3' side of the pivotal uridine in the UA pair frequently forms a noncanonical base pair with a distant residue. The bulged-out bases, usually seen as part of the motif, also use their Watson-Crick edges to interact with nearby residues via base-specific hydrogen bonds. In certain occurrences, a backbone reversal is stabilized by specific hydrogen bonds as is observed in the U-turn motifs and the adenosine residue of the key UA pair interacts with a third base via its Watson-Crick edge, essentially generating a base triple.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
ARN Ribosómico
Idioma:
En
Revista:
RNA
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2002
Tipo del documento:
Article
País de afiliación:
Estados Unidos