title: Independent genes for two threonyl-tRNA synthetases in Bacillus subtilis.
abstract: With the exception of Escherichia coli lysyl-tRNA synthetase, the genes coding for the different aminoacyl-tRNA synthetases in procaryotes are always unique. Here we report on the occurrence and cloning of two genes (thrSv and thrS2), both encoding functional threonyl-tRNA synthetase in Bacillus subtilis. The two proteins share only 51.5% identical residues, which makes them almost as distinct from each other as each is from E. coli threonyl-tRNA synthetase (42 and 47%). Both proteins complement an E. coli thrS mutant and effectively charge E. coli threonyl tRNA in vitro. Their genes have been mapped to 250 degrees (thrSv) and 344 degrees (thrS2) on the B. subtilis chromosome. The regulatory regions of both genes are quite complex and show structural similarities. During vegetative growth, only the thrSv gene is expressed.
authors.affiliation: Institut de Biologie Physico-Chimique, Paris, France.
authors.forename: H
authors.initials: H
authors.lastname: Putzer
authors.forename: A A
authors.initials: AA
authors.lastname: Brakhage
authors.forename: M
authors.initials: M
authors.lastname: Grunberg-Manago
mesh_terms: D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics*; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D007527:Isoenzymes / Q000235:genetics*; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D013914:Threonine-tRNA Ligase / Q000235:genetics*; D014169:Transformation, Bacterial
chemical_list: D004269:DNA, Bacterial; D007527:Isoenzymes; D000604:Amino Acyl-tRNA Synthetases; D013914:Threonine-tRNA Ligase