Reduction of methionine sulfoxide to methionine by Escherichia coli.
L-Methionine-dl-sulfoxide can support the growth of an Escherichia coli methionine auxotroph, suggesting the presence of an enzyme(s) capable of reducing the sulfoxide to methionine. This was verified by showing that a cell-free extract of E. coli catalyzes the conversion of methionine sulfoxide to methionine. This reaction required reduced nicotinamide adenine dinucleotide phosphate and a generating system for this compound. The specific activity of the enzyme increased during logarithmic growth and was maximal when the culture attained a density of about 10(9) cells per ml.
D004926:Escherichia coli / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D005958:Glucosephosphates / Q000378:metabolism; D007700:Kinetics; D008715:Methionine / Q000031:analogs & derivatives* / Q000378:metabolism; D009249:NADP / Q000494:pharmacology; D013454:Sulfoxides / Q000378:metabolism*
D005958:Glucosephosphates; D013454:Sulfoxides; D009249:NADP; D008715:Methionine