title: Structural studies of ROK fructokinase YdhR from Bacillus subtilis: insights into substrate binding and fructose specificity.
abstract: The main pathway of bacterial sugar phosphorylation utilizes specific phosphoenolpyruvate phosphotransferase system (PTS) enzymes. In addition to the classic PTS system, a PTS-independent secondary system has been described in which nucleotide-dependent sugar kinases are used for monosaccharide phosphorylation. Fructokinase (FK), which phosphorylates d-fructose with ATP as a cofactor, has been shown to be a member of this secondary system. Bioinformatic analysis has shown that FK is a member of the "ROK" (bacterial Repressors, uncharacterized Open reading frames, and sugar Kinases) sequence family. In this study, we report the crystal structures of ROK FK from Bacillus subtilis (YdhR) (a) apo and in the presence of (b) ADP and (c) ADP/d-fructose. All structures show that YdhR is a homodimer with a monomer composed of two similar α/β domains forming a large cleft between domains that bind ADP and D-fructose. Enzymatic activity assays support YdhR function as an ATP-dependent fructose kinase.
authors.affiliation: Midwest Center for Structural Genomics and Structural Biology Center, Biosciences, Argonne National Laboratory, 9700 South Cass Avenue, Building 202, Argonne, IL 60439, USA.
authors.forename: B
authors.initials: B
authors.lastname: Nocek
authors.forename: A J
authors.initials: AJ
authors.lastname: Stein
authors.forename: R
authors.initials: R
authors.lastname: Jedrzejczak
authors.forename: M E
authors.initials: ME
authors.lastname: Cuff
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: L
authors.initials: L
authors.lastname: Volkart
authors.forename: A
authors.initials: A
authors.lastname: Joachimiak
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005631:Fructokinases / Q000737:chemistry*; D005632:Fructose / Q000737:chemistry*; D008969:Molecular Sequence Data; D011485:Protein Binding; D013379:Substrate Specificity; D054460:rho-Associated Kinases / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D005632:Fructose; D005631:Fructokinases; C046173:fructokinase; D054460:rho-Associated Kinases