Why do two EF-Tu molecules act in the elongation cycle of protein biosynthesis?
In the elongation cycle of bacterial protein biosynthesis, the binding of aminoacyl-tRNA (aa-tRNA) to the A-site of mRNA-programmed ribosomes is mediated by elongation factor Tu (EF-Tu) and associated with the hydrolysis of GTP. Recently, in the case of cognate aa-tRNA, the participation of two GTP molecules has been implicated in this reaction. These are likely to be involved in preventing the indiscriminate binding of aa-tRNA to the ribosomal A-site. This article integrates this unexpected finding with our current knowledge of the structure-function relationships of the macro-molecules involved in the elongation cycle.
Weijland
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S.D.I. 61840 du CNRS, Laboratoire de Biochimie, Ecole Polytechnique, Palaiseau, France.
Parmeggiani
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D010441:Peptide Chain Elongation, Translational; D010444:Peptide Elongation Factor Tu / Q000737:chemistry / Q000502:physiology*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D013329:Structure-Activity Relationship
D012346:RNA, Transfer, Amino Acyl; D010444:Peptide Elongation Factor Tu