Translation initiation from the ribosomal P-site is the specialty of the initiator tRNAs ( tRNA fMet). Presence of the three consecutive G-C base pairs ( G29-C41, G30-C40 and G31-C39) in their anticodon stems, a highly conserved feature of the initiator tRNAs across the three kingdoms of life, has been implicated in their preferential binding to the P-site. How this feature is exploited by ribosomes has remained unclear. Using a genetic screen, we have isolated an Escherichia coli strain, carrying a G122D mutation in folD, which allows initiation with the tRNA(fMet) containing mutations in one, two or all the three G-C base pairs. The strain shows a severe deficiency of methionine and S-adenosylmethionine, and lacks nucleoside methylations in rRNA. Targeted mutations in the methyltransferase genes have revealed a connection between the rRNA modifications and the fundamental process of the initiator tRNA selection by the ribosome.
机构:
Univ Calif Santa Cruz, Ctr Mol Biol RNA, Sinsheimer Labs, Santa Cruz, CA 95064 USAUniv Calif Santa Cruz, Ctr Mol Biol RNA, Sinsheimer Labs, Santa Cruz, CA 95064 USA
Dallas, A
;
Noller, HF
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机构:
Univ Calif Santa Cruz, Ctr Mol Biol RNA, Sinsheimer Labs, Santa Cruz, CA 95064 USAUniv Calif Santa Cruz, Ctr Mol Biol RNA, Sinsheimer Labs, Santa Cruz, CA 95064 USA
机构:
Univ Calif Santa Cruz, Ctr Mol Biol RNA, Sinsheimer Labs, Santa Cruz, CA 95064 USAUniv Calif Santa Cruz, Ctr Mol Biol RNA, Sinsheimer Labs, Santa Cruz, CA 95064 USA
Dallas, A
;
Noller, HF
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h-index: 0
机构:
Univ Calif Santa Cruz, Ctr Mol Biol RNA, Sinsheimer Labs, Santa Cruz, CA 95064 USAUniv Calif Santa Cruz, Ctr Mol Biol RNA, Sinsheimer Labs, Santa Cruz, CA 95064 USA