title: Evolutionary dynamics of tryptophan tRNAs in Mycoplasma capricolum.
abstract: Mycoplasma capricolum uses two tryptophan codons, the "universal" nonsense codon UGA and the universal codon UGG. The bacterium contains two tryptophan tRNAs, one with anticodon UCA, (U: 2'-O-methyl U derivative), and the other with CCA (5'-C: partially 2'-O-methylated). tRNAUCA would translate codons UGA and probably UGG by wobbling. tRNACCA is much less charged by tryptophan in the cells than tRNAUCA, and the intracellular amount of tRNACCA is 5-10 times lower than that of tRNAUCA. The genes for these two tRNAs are separated by a terminator-like structure in a single operon. In vitro transcription experiments suggest that the predominance of tRNAUCA over tRNACCA results from the attenuation of transcription by this terminator-like structure.
authors.affiliation: Department of Biology, Faculty of Science, Nagoya University, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Yamao
authors.forename: S
authors.initials: S
authors.lastname: Iwagami
authors.forename: Y
authors.initials: Y
authors.lastname: Azumi
authors.forename: A
authors.initials: A
authors.lastname: Muto
authors.forename: S
authors.initials: S
authors.lastname: Osawa
authors.forename: N
authors.initials: N
authors.lastname: Fujita
authors.forename: A
authors.initials: A
authors.lastname: Ishihama
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009174:Mycoplasma / Q000235:genetics*; D009690:Nucleic Acid Conformation; D010957:Plasmids; D012345:RNA, Transfer, Amino Acid-Specific / Q000235:genetics*; D012364:RNA, Transfer, Trp / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D012345:RNA, Transfer, Amino Acid-Specific; D012364:RNA, Transfer, Trp; D012321:DNA-Directed RNA Polymerases