title: Crystallization and preliminary X-ray crystallographic analysis of FlhD/FlhC complex from Escherichia coli.
abstract: The heterotetrameric (C(2)D(2)) FlhD/FlhC complex was first discovered as a transcriptional activator of the flagellar genes in Escherichia coli. Recent studies now show that FlhD/FlhC also regulates several non-flagellar target genes in E. coli. The FlhD/FlhC complex also plays several important roles in other microorganisms. The molecular interactions between FlhD and FlhC, as well as the mechanisms by which the complex may vary its DNA-binding specificity, are not clear. Determination of the FlhD/FlhC crystal structure will provide insight into these protein-protein and protein-DNA interactions. The initial steps in this investigation are reported here: the overexpression, purification and crystallization of the FlhD/FlhC complex, the characterization of this crystal form and the recording and processing of an initial diffraction data set. The obtained crystal form of the FlhD/FlhC complex is hexagonal (space group P6(1), unit-cell parameters a = b = 150.5, c = 115.9 A). The crystal density is very low (V(M) = 5.5), with 81.7% of its volume occupied by solvent. A single C(2)D(2) tetramer is present in the crystallographic asymmetric unit. A complete native data set has been collected to 4.5 A resolution.
authors.affiliation: Department of Microbiology and Immunology, University of Illinois, Chicago, IL 60612-7344, USA.
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.forename: P
authors.initials: P
authors.lastname: Matsumura
authors.forename: E M
authors.initials: EM
authors.lastname: Westbrook
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins; D011487:Protein Conformation; D015534:Trans-Activators / Q000737:chemistry*
chemical_list: D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D015534:Trans-Activators; C090552:flhC protein, E coli; C090553:flhD protein, E coli