title: Three-dimensional structure of CheY, the response regulator of bacterial chemotaxis.
abstract: Homologies among bacterial signal transduction proteins suggest that a common mechanism mediates processes such as chemotaxis, osmoregulation, sporulation, virulence, and responses to nitrogen, phosphorous and oxygen deprivation. A common kinase-mediated phosphotransfer reaction has recently been identified in chemotaxis, nitrogen regulation, and osmoregulation. In chemotaxis, the CheA kinase passes a phosphoryl group to the cytoplasmic protein CheY, which functions as a phosphorylation-activated switch that interacts with flagellar components to regulate motility. We report here the X-ray crystal structure of the Salmonella typhimurium CheY protein. The determination of the structure was facilitated by the use of site-specific mutagenesis to engineer heavy-atom binding sites. CheY is a single-domain protein composed of a doubly wound five-stranded parallel beta-sheet. The phosphoacceptor site in CheY is probably a cluster of aspartic-acid side chains near the C-terminal edge of the beta-sheet. The pattern of sequence similarity of CheY with components of other regulatory systems can be interpreted in the light of the CheY structure and supports the view that this family of proteins have a common structural motif and active site.
authors.affiliation: Department of Chemistry, Princeton University, New Jersey 08544.
authors.forename: A M
authors.initials: AM
authors.lastname: Stock
authors.forename: J M
authors.initials: JM
authors.lastname: Mottonen
authors.forename: J B
authors.initials: JB
authors.lastname: Stock
authors.forename: C E
authors.initials: CE
authors.lastname: Schutt
mesh_terms: D001426:Bacterial Proteins; D002630:Chemotactic Factors; D002633:Chemotaxis; D003198:Computer Simulation; D003461:Crystallography; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D000071677:Histidine Kinase; D046911:Macromolecular Substances; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; D012486:Salmonella typhimurium; D015398:Signal Transduction; D014961:X-Ray Diffraction
chemical_list: D001426:Bacterial Proteins; D002630:Chemotactic Factors; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C000607606:cheY protein, E coli; D000071677:Histidine Kinase; C000607608:cheA protein, E coli