Elongation factors on the ribosome.

University of Aarhus, Department of Molecular Biology, Gustav Wieds Vej 10C, 8000 Arhus C, Denmark.
Current Opinion in Structural Biology (Impact Factor: 8.75). 07/2005; 15(3):349-54. DOI: 10.1016/
Source: PubMed

ABSTRACT The ribosome is a complex macromolecular assembly capable of translating mRNA sequence into amino acid sequence. The adaptor molecule of translation is tRNA, but the delivery of aminoacyl-tRNAs--the primary substrate of the ribosome--relies on the formation of a ternary complex with elongation factor Tu (EF-Tu) and GTP. Likewise, elongation factor G (EF-G) is required to reset the elongation cycle through the translocation of tRNAs. Recent structures and biochemical data on ribosomes in complex with the ternary complex or EF-G have shed light on the mode of action of the elongation factors, and how this interplays with the state of tRNAs and the ribosome. A model emerges of the specific routes of conformational changes mediated by tRNA and the ribosome that trigger the GTPase activity of the elongation factors on the ribosome.

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