Hinge stiffness is a barrier to RNA folding.
J Mol Biol
; 379(4): 859-70, 2008 Jun 13.
Article
en En
| MEDLINE
| ID: mdl-18471829
ABSTRACT
Cation-mediated RNA folding from extended to compact, biologically active conformations relies on a temporal balance of forces. The Mg2 +-mediated folding of the Tetrahymena thermophila ribozyme is characterized by rapid nonspecific collapse followed by tertiary-contact-induced compaction. This article focuses on an autonomously folding portion of the Tetrahymena ribozyme, its P4-P6 domain, in order to probe one facet of the rapid collapse chain flexibility. The time evolution of P4-P6 folding was followed by global and local measures as a function of Mg2 + concentration. While all concentrations of Mg2 + studied are sufficient to screen the charge on the helices, the rates of compaction and tertiary contact formation diverge as the concentration of Mg2 + increases; collapse is greatly accelerated by Mg2 +, while tertiary contact formation is not. These studies highlight the importance of chain stiffness to RNA folding; at 10 mM Mg2 +, a stiff hinge limits the rate of P4-P6 folding. At higher magnesium concentrations, the rate-limiting step shifts from hinge bending to tertiary contact formati
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
ARN
/
Conformación de Ácido Nucleico
Límite:
Animals
Idioma:
En
Revista:
J Mol Biol
Año:
2008
Tipo del documento:
Article
País de afiliación:
Estados Unidos