title: Oxidation of cysteine 645 of cobalamin-independent methionine synthase causes a methionine limitation in Escherichia coli.
abstract: Cobalamin-independent methionine synthase (MetE) catalyzes the final step in Escherichia coli methionine biosynthesis but is inactivated under oxidative conditions, triggering a methionine deficiency. This study demonstrates that the mutation of MetE cysteine 645 to alanine completely eliminates the methionine auxotrophy imposed by diamide treatment, suggesting that modulation of MetE activity via cysteine 645 oxidation has significant physiological consequences for oxidatively stressed cells.
authors.affiliation: Life Sciences Institute, Department of Biological Chemistry and Biophysics Research Division, The University of Michigan, 210 Washtenaw Ave., Ann Arbor, Michigan 48109-2216, USA. ehondorp@umd.edu
authors.forename: Elise R
authors.initials: ER
authors.lastname: Hondorp
authors.forename: Rowena G
authors.initials: RG
authors.lastname: Matthews
mesh_terms: D000409:Alanine / Q000235:genetics / Q000502:physiology; D003545:Cysteine / Q000235:genetics / Q000502:physiology*; D003958:Diamide / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism*; D008780:Methyltransferases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010084:Oxidation-Reduction / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D003958:Diamide; D008715:Methionine; D008780:Methyltransferases; C022725:5-methyltetrahydropteroyltriglutamate-homocysteine S-methyltransferase; D003545:Cysteine; D000409:Alanine