title: Acetohydroxy acid synthase I is required for isoleucine and valine biosynthesis by Salmonella typhimurium LT2 during growth on acetate or long-chain fatty acids.
abstract: Salmonella typhimurium LT2 normally expresses two acetohydroxy acid synthases (AHAS I and AHAS II). The function of AHAS I in this organism was unclear, since AHAS I-deficient (ilvBN) mutants of LT2 grew well on glucose or succinate minimal media, whereas AHAS II-deficient (ilvGM) mutants requried isoleucine for normal growth on glucose minimal media. We report that AHAS I-deficient mutants of S. typhimurium required isoleucine and valine for growth on acetate or oleate minimal media, whereas AHAS II-deficient mutants were able to grow on these media without isoleucine supplementation.
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000095:Acetolactate Synthase / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D005838:Genotype; D007532:Isoleucine / Q000096:biosynthesis*; D007652:Oxo-Acid-Lyases / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D014633:Valine / Q000096:biosynthesis*
chemical_list: D000085:Acetates; D005230:Fatty Acids, Nonesterified; D007532:Isoleucine; D000095:Acetolactate Synthase; D007652:Oxo-Acid-Lyases; D014633:Valine