Kam Bo Wong
The Chinese University of Hong Kong, China
Title: How urease accessory proteins coupled GTP hydrolysis/binding to nickel delivery to urease?
Biography
Biography: Kam Bo Wong
Abstract
Urease is a nickel-containing metalloenzyme that catalyzes the hydrolysis of urea into ammonia and carbon dioxide. Th is
enzymatic reaction, which produces the acid-neutralizing ammonia, is essential for the survival of Helicobacter pylori in
human stomach. In Helicobacter pylori, nickel ions delivery for urease maturation is assisted by four urease accessory proteins,
UreE, UreF, UreG and UreH. Specifi c protein-protein interactions among these urease accessory proteins are essential for the
control of binding/release of nickel along the metal delivery pathway. We have previously determined the crystal structures of
UreF/UreH and GDP-bound-UreG/UreF/UreH complexes. Upon binding of UreH, the C-terminal residues of UreF are induced
to form an extra helix and a loop structure stabilized by Arg-250. Th ese conformational changes facilitate the recruitment of
UreG to the UreG/UreF/UreH complex, which is essential to urease maturation. Recently, we have determined the crystal
structure of the nickel/GTP-bound UreG dimer, which reveals how GTP hydrolysis induces conformational changes that
induce dissociation of UreG from the UreG/UreF/UreH complex and the release of nickel to the urease.