title: Unraveling the Helicobacter pylori UreG zinc binding site using X-ray absorption spectroscopy (XAS) and structural modeling.
abstract: The pathogenicity of Helicobacter pylori depends on the activity of urease for pH modification. Urease activity requires assembly of a dinickel active site that is facilitated in part by GTP hydrolysis by UreG. The proper functioning of Helicobacter pylori UreG (HpUreG) is dependent on Zn(II) binding and dimerization. X-ray absorption spectroscopy and structural modeling were used to elucidate the structure of the Zn(II) site in HpUreG. These studies independently indicated a site at the dimer interface that has trigonal bipyramidal geometry and is composed of two axial cysteines at 2.29(2) Å, two equatorial histidines at 1.99(1) Å, and a solvent-accessible coordination site. The final model for the Zn(II) site structure was determined by refining multiple-scattering extended X-ray absorption fine structure fits using the geometry predicted by homology modeling and ab initio calculations.
authors: Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA.
authors: Vlad
authors: V
authors: Martin-Diaconescu
authors: Matteo
authors: M
authors: Bellucci
authors: Francesco
authors: F
authors: Musiani
authors: Stefano
authors: S
authors: Ciurli
authors: Michael J
authors: MJ
authors: Maroney
mesh_terms: D001665:Binding Sites; D003198:Computer Simulation; D016480:Helicobacter pylori / Q000201:enzymology*; D008958:Models, Molecular; D014510:Urease / Q000737:chemistry / Q000378:metabolism; D056928:X-Ray Absorption Spectroscopy; D015032:Zinc / Q000737:chemistry / Q000378:metabolism
chemical_list: D014510:Urease; D015032:Zinc