title: Structure of the CheY-binding domain of histidine kinase CheA in complex with CheY.
abstract: Bacterial adaptation to the environment is accomplished through the coordinated activation of specific sensory receptors and signal processing proteins. Among the best characterized of these pathways are those which employ the two-component paradigm. In these systems, signal transmission is mediated by Mg(2+)-dependent phospho-relay reactions between histidine auto-kinases and phospho-accepting receiver domains in response-regulator proteins. Although this mechanism of activation is common to all response-regulators, detrimental cross-talk between different two-component pathways within the same cell is minimized through the use of specific recognition domains. Here, we report the crystal structure, at 2.95 A resolution, of the response regulator of bacterial chemotaxis, CheY, bound to the recognition domain from its cognate histidine kinase, CheA. The structure suggests that molecular recognition, in this low affinity complex (KD = 2 microM), may also contribute to the mechanism of CheY activation.
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale CNRS, UPR9062, Toulouse, France.
authors.forename: M
authors.initials: M
authors.lastname: Welch
authors.forename: N
authors.initials: N
authors.lastname: Chinardet
authors.forename: L
authors.initials: L
authors.lastname: Mourey
authors.forename: C
authors.initials: C
authors.lastname: Birck
authors.forename: J P
authors.initials: JP
authors.lastname: Samama
mesh_terms: D000595:Amino Acid Sequence; D001059:Apoproteins / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000648:ultrastructure; D002633:Chemotaxis; D018360:Crystallography, X-Ray; D019281:Dimerization; D000071677:Histidine Kinase; D006860:Hydrogen Bonding; D008565:Membrane Proteins / Q000648:ultrastructure*; D000072236:Methyl-Accepting Chemotaxis Proteins; D008969:Molecular Sequence Data; D011485:Protein Binding; D011494:Protein Kinases / Q000648:ultrastructure*; D017433:Protein Structure, Secondary; D015398:Signal Transduction
chemical_list: D001059:Apoproteins; D001426:Bacterial Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase