2pmc
Crystal Structure of CheY-Mg(2+) in Complex with CheZ(C15) Peptide solved from a P1 Crystal
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OverviewOverview
Chemotaxis, a means for motile bacteria to sense the environment and, achieve directed swimming, is controlled by flagellar rotation. The, primary output of the chemotaxis machinery is the phosphorylated form of, the response regulator CheY (P approximately CheY). The steady-state level, of P approximately CheY dictates the direction of rotation of the, flagellar motor. The chemotaxis signal in the form of P approximately CheY, is terminated by the phosphatase CheZ. Efficient dephosphorylation of CheY, by CheZ requires two distinct protein-protein interfaces: one involving, the strongly conserved C-terminal helix of CheZ (CheZC) tethering the two, proteins together and the other constituting an active site for catalytic, dephosphorylation. In a previous work (Guhaniyogi J., Robinson V. L. and, Stock A. M. 2006. J. Mol. Biol. 359: 624-645), we presented, high-resolution crystal structures of CheY in complex with the CheZC, peptide that revealed alternate binding modes subject to the, conformational state of CheY. In this study, we report biochemical and, structural data that support the alternate binding mode hypothesis and, identify key recognition elements in the CheY-CheZC interaction. In, addition, we present kinetic studies of CheZC-associated effect on CheY, phosphorylation with its physiologically relevant phosphodonor, the, histidine kinase CheA. Our results indicate mechanistic differences in, phosphotransfer from the kinase CheA versus from small molecule, phosphodonors explaining a modest 2-fold increase of CheY phosphorylation, with the former, observed in this study, relative to a 10-fold increase, previously documented with the latter.
About this StructureAbout this Structure
2PMC is a Protein complex structure of sequences from Salmonella typhimurium with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Interaction of CheY with the C-Terminal Peptide of CheZ., Guhaniyogi J, Wu T, Patel SS, Stock AM, J Bacteriol. 2007 Dec 14;. PMID:18083806
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