GTPase activation of elongation factor EF-Tu by the ribosome during decoding.
EMBO J
; 28(6): 755-65, 2009 Mar 18.
Article
em En
| MEDLINE
| ID: mdl-19229291
ABSTRACT
We have used single-particle reconstruction in cryo-electron microscopy to determine a structure of the Thermus thermophilus ribosome in which the ternary complex of elongation factor Tu (EF-Tu), tRNA and guanine nucleotide has been trapped on the ribosome using the antibiotic kirromycin. This represents the state in the decoding process just after codon recognition by tRNA and the resulting GTP hydrolysis by EF-Tu, but before the release of EF-Tu from the ribosome. Progress in sample purification and image processing made it possible to reach a resolution of 6.4 A. Secondary structure elements in tRNA, EF-Tu and the ribosome, and even GDP and kirromycin, could all be visualized directly. The structure reveals a complex conformational rearrangement of the tRNA in the A/T state and the interactions with the functionally important switch regions of EF-Tu crucial to GTP hydrolysis. Thus, the structure provides insights into the molecular mechanism of signalling codon recognition from the decoding centre of the 30S subunit to the GTPase centre of EF-Tu.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ribossomos
/
Fator Tu de Elongação de Peptídeos
/
Thermus thermophilus
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Alemanha