Format

Send to

Choose Destination
See comment in PubMed Commons below
Acta Crystallogr D Biol Crystallogr. 2011 Aug;67(Pt 8):671-7. doi: 10.1107/S090744491101746X. Epub 2011 Jul 12.

Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae.

Author information

1
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853-1301, USA.

Abstract

The stereospecific oxidative degradation of uric acid to (S)-allantoin has recently been demonstrated to proceed via two unstable intermediates and requires three separate enzymatic reactions. The second step of this reaction, the conversion of 5-hydroxyisourate (HIU) to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline, is catalyzed by HIU hydrolase (HIUH). The high-resolution crystal structure of HIUH from the opportunistic pathogen Klebsiella pneumoniae (KpHIUH) has been determined. KpHIUH is a homotetrameric protein that, based on sequence and structural similarity, belongs to the transthyretin-related protein family. In addition, the steady-state kinetic parameters for this enzyme and four active-site mutants have been measured. These data provide valuable insight into the functional roles of the active-site residues. Based upon the structural and kinetic data, a mechanism is proposed for the KpHIUH-catalyzed reaction.

PMID:
21795808
PMCID:
PMC3144850
DOI:
10.1107/S090744491101746X
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for International Union of Crystallography Icon for PubMed Central
    Loading ...
    Support Center