title: Structural characterization of Helicobacter pylori dethiobiotin synthetase reveals differences between family members.
abstract: Dethiobiotin synthetase (DTBS) is involved in the biosynthesis of biotin in bacteria, fungi, and plants. As humans lack this pathway, DTBS is a promising antimicrobial drug target. We determined structures of DTBS from Helicobacter pylori (hpDTBS) bound with cofactors and a substrate analog, and described its unique characteristics relative to other DTBS proteins. Comparison with bacterial DTBS orthologs revealed considerable structural differences in nucleotide recognition. The C-terminal region of DTBS proteins, which contains two nucleotide-recognition motifs, differs greatly among DTBS proteins from different species. The structure of hpDTBS revealed that this protein is unique and does not contain a C-terminal region containing one of the motifs. The single nucleotide-binding motif in hpDTBS is similar to its counterpart in GTPases; however, isothermal titration calorimetry binding studies showed that hpDTBS has a strong preference for ATP. The structural determinants of ATP specificity were assessed with X-ray crystallographic studies of hpDTBS·ATP and hpDTBS·GTP complexes. The unique mode of nucleotide recognition in hpDTBS makes this protein a good target for H. pylori-specific inhibitors of the biotin synthesis pathway.
authors.affiliation: Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA.
authors.forename: Przemyslaw J
authors.initials: PJ
authors.lastname: Porebski
authors.forename: Maria
authors.initials: M
authors.lastname: Klimecka
authors.forename: Maksymilian
authors.initials: M
authors.lastname: Chruszcz
authors.forename: Robert A
authors.initials: RA
authors.lastname: Nicholls
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Murzyn
authors.forename: Marianne E
authors.initials: ME
authors.lastname: Cuff
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Xu
authors.forename: Marcin
authors.initials: M
authors.lastname: Cymborowski
authors.forename: Garib N
authors.initials: GN
authors.lastname: Murshudov
authors.forename: Alexei
authors.initials: A
authors.lastname: Savchenko
authors.forename: Aled
authors.initials: A
authors.lastname: Edwards
authors.forename: Wladek
authors.initials: W
authors.lastname: Minor
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D019731:Carbon-Nitrogen Ligases / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D016480:Helicobacter pylori / Q000201:enzymology*; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D000255:Adenosine Triphosphate; D019731:Carbon-Nitrogen Ligases; C020024:dethiobiotin synthetase