title: A second global regulator gene (arcB) mediating repression of enzymes in aerobic pathways of Escherichia coli.
abstract: In Escherichia coli anaerobic growth lowers the basal or induced levels of numerous enzymes associated with aerobic metabolism. Mutations in arcA (dye) at min 0 relieve this pleiotropic anaerobic repression and render the cell sensitive to the redox dye toluidine blue. In this study we identified a second pleiotropic control gene, arcB, at min 69.5. Mutations, including a deletion, in this gene also relieved the anaerobic repression and caused sensitivity to toluidine blue. Mutations in arcA or arcB did not significantly change the catabolite repression of the target phi(sdh-lacZ) operon, in which lacZ is fused to a structural gene for succinate dehydrogenase, nor did the mutations strikingly influence the pattern of excretion products during glucose fermentation. The presence of arcA+ in a multicopy plasmid restored anaerobic repression in arcB mutants, as indicated by the expression of phi(sdh-lacZ). The arcB product might be a sensor protein for the redox or energy state of the arc regulatory system.
authors.affiliation: Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115.
authors.forename: S
authors.initials: S
authors.lastname: Iuchi
authors.forename: D C
authors.initials: DC
authors.lastname: Cameron
authors.forename: E C
authors.initials: EC
authors.lastname: Lin
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D004794:Enzyme Repression; D004798:Enzymes / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D005796:Genes; D005798:Genes, Bacterial; D005809:Genes, Regulator; D009154:Mutation; D010084:Oxidation-Reduction; D015183:Restriction Mapping
chemical_list: D004798:Enzymes