Biochemical and structural characterization of Klebsiella pneumoniae oxamate amidohydrolase in the uric acid degradation pathway.
Publication Type:Journal Article
Source:Acta Crystallogr D Struct Biol, Volume 72, Issue Pt 6, p.808-16 (2016)
Keywords:Amidohydrolases, Catalytic Domain, Crystallography, X-Ray, Humans, Klebsiella Infections, Klebsiella pneumoniae, Models, Molecular, Protein Conformation, Substrate Specificity, Uric Acid
<p>HpxW from the ubiquitous pathogen Klebsiella pneumoniae is involved in a novel uric acid degradation pathway downstream from the formation of oxalurate. Specifically, HpxW is an oxamate amidohydrolase which catalyzes the conversion of oxamate to oxalate and is a member of the Ntn-hydrolase superfamily. HpxW is autoprocessed from an inactive precursor to form a heterodimer, resulting in a 35.5 kDa α subunit and a 20 kDa β subunit. Here, the structure of HpxW is presented and the substrate complex is modeled. In addition, the steady-state kinetics of this enzyme and two active-site variants were characterized. These structural and biochemical studies provide further insight into this class of enzymes and allow a mechanism for catalysis consistent with other members of the Ntn-hydrolase superfamily to be proposed.</p>