Unconventional decoding of the AUA codon as methionine by mitochondrial tRNAMet with the anticodon f5CAU as revealed with a mitochondrial in vitro translation system.

ABSTRACT: Mitochondrial (mt) tRNA(Met) has the unusual modified nucleotide 5-formylcytidine (f(5)C) in the first position of the anticodon. This tRNA must translate both AUG and AUA as methionine. By constructing an in vitro translation system from bovine liver mitochondria, we examined the decoding properties of the native mt tRNA(Met) carrying f(5)C in the anticodon compared to a transcript that lacks the modification. The native mt Met-tRNA could recognize both AUA and AUG codons as Met, but the corresponding synthetic tRNA(Met) lacking f(5)C (anticodon CAU), recognized only the AUG codon in both the codon-dependent ribosomal binding and in vitro translation assays. Furthermore, the Escherichia coli elongator tRNA(Met)(m) with the anticodon ac(4)CAU (ac(4)C = 4-acetylcytidine) and the bovine cyto

SUBMITTER: Takemoto C 

PROVIDER: S-EPMC2655697 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature