title: Crystallization and preliminary X-ray crystallographic analysis of Escherichia coli CheA P3 dimerization domain.
abstract: The chemotaxis histidine kinase CheA assembles into a dimer in which the P3 dimerization domain forms a four-helix bundle by the parallel association of two α-helical hairpins from each subunit. Ligand occupancy of the chemoreceptor regulates signal transduction by controlling the autophosphorylation activity of CheA. Autophosphorylation of CheA occurs in trans, i.e. one subunit phosphorylates the other. The P3 domain of CheA from Escherichia coli has been overexpressed in E. coli and crystallized at 298 K using PEG as a precipitant. X-ray diffraction data to 2.80 Å resolution have been collected at 100 K using synchrotron radiation. The crystal belonged to space group P1, with unit-cell parameters a = 59.271, b = 67.674, c = 82.815 Å, α = 77.568, β = 86.073, γ = 64.436°. The asymmetric unit may contain up to ten dimeric units of P3 four-helix bundles.
authors.affiliation: School of Systems Biomedical Science, Soongsil University, 511 Sangdo-Dong, Dongjak-Gu, Seoul, South Korea. psy@ssu.ac.kr
authors.forename: Sang Youn
authors.initials: SY
authors.lastname: Park
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Ham
authors.forename: Keon Young
authors.initials: KY
authors.lastname: Kim
authors.forename: Brian R
authors.initials: BR
authors.lastname: Crane
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D000071677:Histidine Kinase; D008565:Membrane Proteins / Q000737:chemistry*; D000072236:Methyl-Accepting Chemotaxis Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; D000071677:Histidine Kinase; C000607608:cheA protein, E coli