title: Solution structure of a complex of the histidine autokinase CheA with its substrate CheY.
abstract: In the bacterial chemotaxis two-component signaling system, the histidine-containing phosphotransfer domain (the "P1" domain) of CheA receives a phosphoryl group from the catalytic domain (P4) of CheA and transfers it to the cognate response regulator (RR) CheY, which is docked by the P2 domain of CheA. Phosphorylated CheY then diffuses into the cytoplasm and interacts with the FliM moiety of the flagellar motors, thereby modulating the direction of flagellar rotation. Structures of various histidine phosphotransfer domains (HPt) complexed with their cognate RR domains have been reported. Unlike the Escherichia coli chemotaxis system, however, these systems lack the additional domains dedicated to binding to the response regulators, and the interaction of an HPt domain with an RR domain in the presence of such a domain has not been examined on a structural basis. In this study, we used modern nuclear magnetic resonance techniques to construct a model for the interaction of the E. coli CheA P1 domain (HPt) and CheY (RR) in the presence of the CheY-binding domain, P2. Our results indicate that the presence of P2 may lead to a slightly different relative orientation of the HPt and RR domains versus those seen in such complex structures previously reported.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106-9510, USA.
authors.forename: Guoya
authors.initials: G
authors.lastname: Mo
authors.forename: Hongjun
authors.initials: H
authors.lastname: Zhou
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kawamura
authors.forename: Frederick W
authors.initials: FW
authors.lastname: Dahlquist
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D029968:Escherichia coli Proteins; D000071677:Histidine Kinase; D007700:Kinetics; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D000072236:Methyl-Accepting Chemotaxis Proteins; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D011494:Protein Kinases / Q000737:chemistry*; D017434:Protein Structure, Tertiary / Q000502:physiology; D013050:Spectrometry, Fluorescence
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C000607606:cheY protein, E coli; D011494:Protein Kinases; C091973:autophosphorylation-dependent multifunctional protein kinase; D000071677:Histidine Kinase; C000607608:cheA protein, E coli