title: Genetically determined differences in concentrations of isoaccepting tRNAs in Escherichia coli.
abstract: Two examples of genetically determined altered concentrations of isoaccepting tRNAs are presented. The concentrations of isoaccepting tRNAsThr are selectively changed by a mutation causing a fourfold overproduction of the cognate aminoacyl-tRNA-synthetase, the threonyl-tRNA synthetase, whereas the distribution of isoaccepting tRNAs of four control tRNA-species in these E. coli mutants was not affected by that mutation. Secondly evidence is presented for a correlation between mutations in structural genes of aminoacid biosynthetic enzymes and alterations in concentrations of cognate isoaccepting tRNAs in two different E. coli strains, auxotrophic for threonine, isoleucine/valine and leucine, and arginine respectively.
mesh_terms: D001120:Arginine; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D007532:Isoleucine; D007930:Leucine; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity; D013912:Threonine
chemical_list: D007532:Isoleucine; D013912:Threonine; D012343:RNA, Transfer; D001120:Arginine; D007930:Leucine