Crucial contribution of the multiple copies of the initiator tRNA genes in the fidelity of tRNA(fMet) selection on the ribosomal P-site in Escherichia coli.

ABSTRACT: The accuracy of the initiator tRNA (tRNA(fMet)) selection in the ribosomal P-site is central to the fidelity of protein synthesis. A highly conserved occurrence of three consecutive G-C base pairs in the anticodon stem of tRNA(fMet) contributes to its preferential selection in the P-site. In a genetic screen, using a plasmid borne copy of an inactive tRNA(fMet) mutant wherein the three G-C base pairs were changed, we isolated Escherichia coli strains that allow efficient initiation with the tRNA(fMet) mutant. Here, extensive characterization of two such strains revealed novel mutations in the metZWV promoter severely compromising tRNA(fMet) levels. Low cellular abundance of the chromosomally encoded tRNA(fMet) allows efficient initiation with the tRNA(fMet) mutant and an elongator tRNA(Gln

SUBMITTER: Kapoor S 

PROVIDER: S-EPMC3017606 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature