title: Purification and preliminary X-ray crystallographic analysis of the ligand-binding domain of Sinorhizobium meliloti DctB.
abstract: Sinorhizobium meliloti DctBD is a well-characterized two-component system. It is believed that DctB senses the concentration of C4-dicarboxylate compounds on the outside of the bacterium and phosphorylates DctD, which in turn activates transcription of the dctA gene, coding for a gene of C4-dicarboxylate permease. The structure and function of the ligand-binding domain of DctB has not been thoroughly investigated. In this study, this domain was produced in E. coli in soluble form, and purified to homogeneity. Crystals were obtained by hanging-drop vapor-diffusion method. The crystals diffracted to 2.3 A resolution and belonged to P42 space group with unit cell dimensions of a = b = 71.77 A, c = 227.14 A. The asymmetric unit contains four molecules with a corresponding VM of 2.4 A3 Da(-1) and a solvent content of 49.1%.
authors.affiliation: National laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Beiyan
authors.initials: B
authors.lastname: Nan
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yu-He
authors.initials: YH
authors.lastname: Liang
authors.forename: Jin
authors.initials: J
authors.lastname: Wen
authors.forename: Qi
authors.initials: Q
authors.lastname: Ma
authors.forename: Siwei
authors.initials: S
authors.lastname: Zhang
authors.forename: Yiping
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Su
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D018360:Crystallography, X-Ray; D029382:Dicarboxylic Acid Transporters / Q000737:chemistry* / Q000302:isolation & purification*; D008024:Ligands; D011485:Protein Binding; D016962:Sinorhizobium meliloti / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D029382:Dicarboxylic Acid Transporters; D008024:Ligands; C073787:DCTB protein, Sinorhizobium