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. This 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. Specific 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. These 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.
References:
1. Fong Y H, Wong H C, Chuck C P, Chen Y W, Sun H, Wong K B (2011) Assembly of preactivation complex for urease maturation in Helicobacter pylori: crystal structure of UreF-UreH protein complex. Journal of Biological Chemistry. 286(50):43241-43249.
2. Fong Y H, Wong H C, Yuen M H, Lau P H, Chen Y W, Wong K B (2013) Structure of UreG/UreF/UreH complex reveals how urease accessory proteins facilitate maturation of Helicobacter pylori urease. PLoS Biology. 11(10):e1001678.
3. Luo F, Fong Y H, Zeng Y, Shen J, Jiang L, Wong KB (2014) How vacuolar sorting proteins interact with their cargo proteins: crystal structures of apo and cargo-bound forms of the protease-associated domain from an Arabidopsis vacuolar sorting receptor. Plant Cell. 26(9):3693-3708.
4. Lee K M, Yu C W H, Chiu T Y H, Sze K H, Shaw P C, Wong K B (2012) Solution structure of the dimerization domain of the eukaryotic stalk P1/P2 complex reveals the structural organization of eukaryotic stalk complex. Nucleic Acids Research. 40(7):3172-3182.