title: Methionine sulfoxide is transported by high-affinity methionine and glutamine transport systems in Salmonella typhimurium.
abstract: Three lines of evidence indicated that methionine sulfoxide is transported by the high-affinity methionine and glutamine transport systems in Salmonella typhimurium. First, methionine-requiring strains (metE) which have mutations affecting both of these transport systems (metP glnP) were unable to use methionine sulfoxide as a source of methionine. These strains could still grow on L-methionine because they possessed a low-affinity system (or systems) which transported L-methionine but not the sulfoxide. A methionine auxotroph with a defect only in the metP system, which was dependent upon the glnP+ system for the transport of methionine sulfoxide, was inhibited by L-glutamine because glutamine inhibited the transport of the sulfoxide by the glnP+ system. Second, a metE metP glnP strain could be transduced at either the metP or glnP genes to restore its ability to grow on methionine sulfoxide. Third, the transport of [14C]methionine sulfoxide was inhibited by methionine and by glutamine in the metP+ glnP+ strain. No transport was detected in the metP glnP double-mutant strain.
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D005798:Genes, Bacterial; D005973:Glutamine / Q000378:metabolism* / Q000494:pharmacology; D008715:Methionine / Q000031:analogs & derivatives* / Q000378:metabolism*; D009154:Mutation; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism*; D013454:Sulfoxides / Q000378:metabolism
chemical_list: D013454:Sulfoxides; D005973:Glutamine; D008715:Methionine; C013111:methionine sulfoxide