title: Structure and catalytic mechanism of the E. coli chemotaxis phosphatase CheZ.
abstract: The protein CheZ, which has the last unknown structure in the Escherichia coli chemotaxis pathway, stimulates the dephosphorylation of the response regulator CheY by an unknown mechanism. Here we report the co-crystal structure of CheZ with CheY, Mg(2+) and the phosphoryl analog, BeF(3)(-). The predominant structural feature of the CheZ dimer is a long four-helix bundle composed of two helices from each monomer. The side chain of Gln 147 of CheZ inserts into the CheY active site and is essential to the dephosphorylation activity of CheZ. Gln 147 may orient a water molecule for nucleophilic attack, similar to the role of the conserved Gln residue in the RAS family of GTPases. Similarities between the CheY[bond] CheZ and Spo0F [bond]Spo0B structures suggest a general mode of interaction for modulation of response regulator phosphorylation chemistry.
authors.affiliation: Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, 27599-7290 USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhao
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Collins
authors.forename: Robert B
authors.initials: RB
authors.lastname: Bourret
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Silversmith
mesh_terms: D001426:Bacterial Proteins; D002384:Catalysis; D002633:Chemotaxis; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000072236:Methyl-Accepting Chemotaxis Proteins; D008958:Models, Molecular; D009154:Mutation; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D055672:Static Electricity; D018631:ras Proteins / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C000607606:cheY protein, E coli; D010744:Phosphoric Monoester Hydrolases; D018631:ras Proteins