Functional disruption of HypB, a GTPase of Helicobacter pylori, by bismuth

Abstract

Bismuth (Bi³⁺) binds equal molar amounts of HypB from Helicobacter pylori at the conserved metal site with a dissociation constant of 0.94 (±0.25) × 10⁻¹⁷ μM, and concomitantly induces the protein dimerization similarly to Ni²⁺. Excess Bi³⁺ causes HypB further oligomerization, leading to HypB GTPase dysfunction. The results extend our understanding on the inhibitory mechanism of bismuth drugs against the pathogen.