title: Role of His243 in the phosphatase activity of EnvZ in Escherichia coli.
abstract: EnvZ undergoes autophosphorylation at His243 and subsequently transfers the phosphate group to OmpR. EnvZ also possesses an OmpR-phosphate phosphatase activity. We examined the role of His243 in the phosphatase function by replacing His with either Val, Tyr, Ser, Asp, or Asn. EnvZH243V and EnvZH243Y were both shown to possess phosphatase activity in vitro. In addition, the mutant proteins were able to reduce the high level of OmpR-phosphate present in the envZ473 strain. These results indicate that His243 of EnvZ is not essential for stimulating the dephosphorylation of OmpR-phosphate.
authors.affiliation: Department of Biological Sciences, University of Wisconsin--Milwaukee, 53201, USA.
authors.forename: K
authors.initials: K
authors.lastname: Skarphol
authors.forename: J
authors.initials: J
authors.lastname: Waukau
authors.forename: S A
authors.initials: SA
authors.lastname: Forst
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D006639:Histidine / Q000378:metabolism*; D009097:Multienzyme Complexes; D016296:Mutagenesis; D009154:Mutation; D010749:Phosphoprotein Phosphatases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D010766:Phosphorylation
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D006639:Histidine; C057843:envZ protein, E coli; D010749:Phosphoprotein Phosphatases