title: Evolution of tRNAs and tRNA genes in Acholeplasma laidlawii.
abstract: The genes for 22 tRNA species from Acholeplasma laidawii, belonging to the class Mollicutes (Mycoplasmas), have been cloned and sequenced. Sixteen genes are organized in 3 clusters consisting of eleven, three and two tRNA genes, respectively, and the other 6 genes exist as a single gene. The arrangement of tRNA genes in the 11-gene, the 3-gene and the 2-gene clusters reveals extensive similarity to several parts of the 21-tRNA or 16-tRNA gene cluster in Bacillus subtilis. The 11-gene cluster is also similar to the tRNA gene clusters found in other mycoplasma species, the 9-tRNA gene cluster in M.capricolum and in M.mycoides, and the 10-tRNA gene cluster in Spiroplasma meliferm. The results suggest that the tRNA genes in mycoplasmas have evolved from large tRNA gene clusters in the ancestral Gram-positive bacterial genome common to mycoplasmas and B.subtilis. The anticodon sequences including base modifications of 15 tRNA species from A.laidlawii were determined. The anticodon composition and codon-recognition patterns of A.laidlawii resemble those of Bacillus subtilis rather than those of other mycoplasma species.
authors.affiliation: Department of Biology, School of Science, Nagoya University, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Tanaka
authors.forename: Y
authors.initials: Y
authors.lastname: Andachi
authors.forename: A
authors.initials: A
authors.lastname: Muto
mesh_terms: D000128:Acholeplasma laidlawii / Q000235:genetics*; D000926:Anticodon / Q000235:genetics; D001412:Bacillus subtilis / Q000235:genetics; D001483:Base Sequence; D005075:Biological Evolution; D003001:Cloning, Molecular; D003062:Codon / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009174:Mycoplasma / Q000235:genetics; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics*
chemical_list: D000926:Anticodon; D003062:Codon; D012329:RNA, Bacterial; D012343:RNA, Transfer