title: Bases in the anticodon loop of tRNA(Ala)(GGC) prevent misreading.
abstract: The bases at positions 32 and 38 in the tRNA anticodon loop are known to have a specific conservation depending upon the anticodon triplets. Here we report that evolutionarily conserved pairs of bases at positions 32 and 38 in tRNA(Ala)(GGC) prevent misreading of a near-cognate valine codon, GUC. The tRNA(Ala)(GGC) molecules with the conserved A32-U38 and C32-G38 pairs do not read GUC, whereas those with three representative nonconserved pairs, U32-U38, U32-A38 and C32-A38, direct the misincorporation of alanine at this valine codon into the peptide chain. Overexpression of the nonconserved tRNA(Ala)(GGC) in Escherichia coli is toxic and prevents cell growth. These results suggested that the bases at positions 32 and 38 in tRNA(Ala)(GGC) evolved to preserve the fidelity of the cognate codon reading.
authors.affiliation: Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan. hmura@rcast.u-tokyo.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Murakami
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ohta
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suga
mesh_terms: D000409:Alanine / Q000235:genetics / Q000378:metabolism; D000926:Anticodon / Q000235:genetics*; D001483:Base Sequence; D003062:Codon / Q000235:genetics*; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology*; D008958:Models, Molecular; D014176:Protein Biosynthesis; D012344:RNA, Transfer, Ala / Q000235:genetics* / Q000378:metabolism*; D012366:RNA, Transfer, Val / Q000235:genetics / Q000378:metabolism; D014633:Valine / Q000235:genetics / Q000378:metabolism
chemical_list: D000926:Anticodon; D003062:Codon; D012344:RNA, Transfer, Ala; D012366:RNA, Transfer, Val; D014633:Valine; D000409:Alanine