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) A, two equatorial histidines at 1.99(1) A, 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.
V. Martin-Diaconescu, M. Bellucci, F. Musiani, S. Ciurli, M. Maroney (2012). Unraveling the Helicobacter pylori UreG zinc binding site using X-ray absorption spectroscopy (XAS) and structural modeling. JBIC, 17, 353-361 [10.1007/s00775-011-0857-9].
Unraveling the Helicobacter pylori UreG zinc binding site using X-ray absorption spectroscopy (XAS) and structural modeling
BELLUCCI, MATTEO;MUSIANI, FRANCESCO;CIURLI, STEFANO LUCIANO;
2012
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) A, two equatorial histidines at 1.99(1) A, 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
