Temperature-induced derepression of tryptophan biosynthesis in a tryptophanyl-transfer ribonucleic acid synthetase mutant of Bacillus subtilis.
A tryptophanyl-transfer ribonucleic acid (tRNA) synthetase (l-tryptophan: tRNA ligase adenosine monophosphate, EC 6.1.1.2) mutant (trpS1) of Bacillus subtilis is derepressed for enzymes of the tryptophan biosynthetic pathway at temperatures which reduce the growth rate but still allow exponential growth. Derepression of anthranilate synthase in a tryptophan-supplemented medium (50 mug/ml) is maximal at 36 C, and the differential rate of synthesis is 600- to 2,000-fold greater than that of the wild-type strain or trpS1 revertants. A study of the derepression pattern in the mutant and its revertants indicates that the 5-fluorotryptophan recognition site of the tryptophanyl-tRNA synthetase is an integral part of the repression mechanism. Evidence for a second locus, unlinked to the trpS1 locus, which functions in the repression of tryptophan biosynthetic enzymes is presented.
D000604:Amino Acyl-tRNA Synthetases / Q000096:biosynthesis*; D000878:Anthranilate Synthase / Q000096:biosynthesis; D001412:Bacillus subtilis / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002474:Cell-Free System; D003470:Culture Media; D004794:Enzyme Repression; D005796:Genes; D009154:Mutation; D010710:Phosphates; D011868:Radioisotopes; D013696:Temperature; D014161:Transduction, Genetic; D014170:Transformation, Genetic; D014364:Tryptophan / Q000096:biosynthesis* / Q000378:metabolism; D014367:Tryptophan Synthase / Q000096:biosynthesis
D002250:Carbon Radioisotopes; D003470:Culture Media; D010710:Phosphates; D011868:Radioisotopes; D014364:Tryptophan; D000878:Anthranilate Synthase; D014367:Tryptophan Synthase; D000604:Amino Acyl-tRNA Synthetases