Regulation of the metR gene of Salmonella typhimurium.

Regulation of the Salmonella typhimurium metR gene was studied by measuring beta-galactosidase levels in Escherichia coli strains lysogenic for a lambda bacteriophage carrying a metR-lacZ fusion. The results indicate that the metR gene is negatively regulated by its own gene product and that this autoregulation involves homocysteine as a corepressor. In addition, the results indicate that the metR gene is negatively regulated by the metJ gene product over a 70- to 80-fold range.