Quality control by the ribosome following peptide bond formation

Article

关键词: AMINOACYL-TRANSFER-RNA;    ESCHERICHIA-COLI;    CODON RECOGNITION;    RELEASE FACTORS;    E-SITE;    TRANSLATION;    ACCURACY;    DISCRIMINATION;    TERMINATION;    ERRORS;   

DOI  :  10.1038/nature07582

来源: SCIE

【 摘 要 】

The overall fidelity of protein synthesis has been thought to rely on the combined accuracy of two basic processes: the aminoacylation of transfer RNAs with their cognate amino acid by the aminoacyl- tRNA synthetases, and the selection of cognate aminoacyl- tRNAs by the ribosome in cooperation with the GTPase elongation factor EF- Tu. These two processes, which together ensure the specific acceptance of a correctly charged cognate tRNA into the aminoacyl ( A) site, operate before peptide bond formation. Here we report the identification of an additional mechanism that contributes to high fidelity protein synthesis after peptidyl transfer, using a well- defined in vitro bacterial translation system. In this retrospective quality control step, the incorporation of an amino acid from a non- cognate tRNA into the growing polypeptide chain leads to a general loss of specificity in the A site of the ribosome, and thus to a propagation of errors that results in abortive termination of protein synthesis.

【 授权许可】

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