title: Two transcriptionally active OmpR mutants that do not require phosphorylation by EnvZ in an Escherichia coli cell-free system.
abstract: D55Q-T83A and D55Q-G94S, two pseudorevertants of the D55Q mutant OmpR, an Escherichia coli transcriptional activator, were isolated previously by R. Brissette, K. Tsung, and M. Inouye (J. Bacteriol. 173:3749-3755, 1991). These pseudorevertant OmpR proteins were purified and examined for their function as transcriptional activators in a cell-free system with an ompF DNA fragment. These proteins were transcriptionally active, even after acid treatment, whereas the wild-type OmpR was completely inactive after the same treatment. Phosphorylation of acid-treated wild-type OmpR with an EnvZ11 membrane fraction and ATP restored transcriptional activity, whereas the activities of the mutant OmpR proteins did not change after phosphorylation.
authors.affiliation: Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey at Rutgers, Piscataway 08854.
authors.forename: V
authors.initials: V
authors.lastname: Bowrin
authors.forename: R
authors.initials: R
authors.lastname: Brissette
authors.forename: M
authors.initials: M
authors.lastname: Inouye
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D009154:Mutation / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D014157:Transcription Factors; C057843:envZ protein, E coli; D010749:Phosphoprotein Phosphatases