Abstract
The herbicide sulfometuron methyl is a potent inhibitor of the branched-chain amino acid biosynthetic enzyme acetolactate synthase (ALS) isolated from bacteria, fungi, and plants. However, it did not prevent growth of wild-type Salmonella typhimurium LT2 or Escherichia coli K-12. These species each contain two acetolactate synthase isozymes. Growth of S. typhimurium and E. coli mutants lacking ALS I was prevented by the herbicide, suggesting that activity of the remaining ALS isoenzyme (II or III, respectively) was stopped by sulfometuron methyl. Synthesis of ALS I requires either an relA function or an elevated cyclic AMP level. A relA mutant of S. typhimurium was inhibited by sulfometuron methyl on rich carbon sources that display a basal cyclic AMP level but not on poor carbon sources where the cyclic AMP concentration is elevated. When L-valine, which allosterically inhibits ALS I activity, was added, growth retardation of the relA- strain by sulfometuron methyl was observed on both poor and rich carbon sources. Enzymological analyses indicated that ALS I activities derived from both species were resistant to the herbicide. In contrast, activities of S. typhimurium ALS II and E. coli ALS III were abolished by sulfometuron methyl.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference22 articles.
1. Transport of antibiotics and metabolite analogs by systems under cyclic AMP control: positive selection of Salmonella typhimurium cya and c rp mutants;Alper M. D.;J. Bacteriol.,1978
2. Control of isoleucine, leucine and valine biosynthesis. II. End-product inhibition by valine of acetohydroxy acid synthase in Salmonella typhimurium;Bauerle R. H.;Biochim. Biophys. Acta,1964
3. Positive selection for loss of tetracycline resistance;Bochner B. R.;J. Bacteriol.,1980
4. Acetolactate synthase is the site of action of the herbicides chlorsulfuron and sulfometuron methyl in higher plants;Chaleff R. S.;Science,1984
5. Davis R. W. D. Botstein and J. R. Roth. 1980. Advanced bacterial genetics. Cold Spring Harbor Laboratory Cold Spring Harbor N.Y.
Cited by
49 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献