title: The crystallization of apo-form UMP kinase from Xanthomonas campestris is significantly improved in a strong magnetic field.
abstract: Bacterial UMP kinases (UMPKs) are crucial enzymes that are responsible for microbial UTP biosynthesis. Interestingly, eukaryotic and prokaryotic cells use different enzymes for UMP-phosphorylation reactions. Prokaryotic UMPKs are thus believed to be potential targets for antimicrobial drug development. Here, the cloning, expression and crystallization of SeMet-substituted XC1936, a bacterial UMPK from Xanthomonas campestris pathovar campestris, are reported. The crystallization of the apo-form UMPK was found to be significantly improved in a strong magnetic field; the crystals diffracted to a resolution of 2.35 A, a dramatic improvement over the original value of 3.6 A. Preliminary structural analyses of apo-form XC1936 using crystals grown in a strong magnetic field clearly reveal well defined loop regions involved in substrate-analogue binding that were previously not visible. Crystallization in a strong magnetic field thus was found to be indispensable in determining the flexible region of the XC1936 UMPK structure.
authors.affiliation: Institute of Biochemistry, National Chung-Hsing University, Taichung 40227, Taiwan.
authors.forename: Jhe-Le
authors.initials: JL
authors.lastname: Tu
authors.forename: Ko-Hsin
authors.initials: KH
authors.lastname: Chin
authors.forename: Andrew H-J
authors.initials: AH
authors.lastname: Wang
authors.forename: Shan-Ho
authors.initials: SH
authors.lastname: Chou
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D003460:Crystallization; D018360:Crystallography, X-Ray; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D008280:Magnetics; D009703:Nucleoside-Phosphate Kinase / Q000737:chemistry* / Q000235:genetics; D011487:Protein Conformation; D016959:Xanthomonas campestris / Q000201:enzymology*
chemical_list: D017931:DNA Primers; C023276:uridine monophosphate kinase; D009703:Nucleoside-Phosphate Kinase