title: Regulation of histidyl-transfer ribonucleic acid synthetase formation in a histidyl-transfer ribonucleic acid synthetase mutant of Salmonella typhimurium.
abstract: Control of formation of the histidyl-transfer ribonucleic acid (tRNA) synthetase with an increased K(m) for histidine was studied in a hisS mutant of Salmonella typhimurium. Histidine restriction of both the hisS and hisS(+) strains resulted in a derepression of synthesis of histidyl-tRNA synthetase. When grown in a concentration less than the K(m) (100 mug/ml) of l-histidine, the hisS mutant maintained a higher level of histidyl-tRNA synthetase than the hisS(+) strain. Addition of excess amounts of l-histidine to the growth medium of the hisS mutant culture grown with 100 mug of l-histidine per ml resulted in a repression of histidyl-tRNA synthetase formation to equal that of the hisS(+) strain grown in 100 mug of l-histidine per ml. These data confirm previous findings that histidine tRNA is involved in the repression of synthesis of histidyl-tRNA synthetase.
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000032:analysis / Q000096:biosynthesis*; D000605:Amino Alcohols; D003470:Culture Media; D005827:Genetics, Microbial; D005838:Genotype; D006639:Histidine; D007093:Imidazoles; D009154:Mutation; D010084:Oxidation-Reduction; D012486:Salmonella typhimurium / Q000201:enzymology* / Q000378:metabolism
chemical_list: D000605:Amino Alcohols; D003470:Culture Media; D007093:Imidazoles; D006639:Histidine; D000604:Amino Acyl-tRNA Synthetases