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

Abstract

The crystal structure of 5-hydroxyisourate hydrolase from K. pneumoniae and the steady-state kinetic parameters of the native enzyme as well as several mutants provide insights into the catalytic mechanism of this enzyme and the possible roles of the active-site residues. 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.

Authors:
Publication Date:
OSTI Identifier:
22351238
Resource Type:
Journal Article
Journal Name:
Acta Crystallographica. Section D: Biological Crystallography
Additional Journal Information:
Journal Volume: 67; Journal Issue: Pt 8; Other Information: PMCID: PMC3144850; PMID: 21795808; PUBLISHER-ID: hm5097; OAI: oai:pubmedcentral.nih.gov:3144850; Copyright (c) International Union of Crystallography 2011; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0907-4449
Country of Publication:
Denmark
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CONVERSION; CRYSTAL STRUCTURE; RESOLUTION

Citation Formats

French, Jarrod B., and Ealick, Steven E., E-mail: see3@cornell.edu. Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae. Denmark: N. p., 2011. Web. doi:10.1107/S090744491101746X.
French, Jarrod B., & Ealick, Steven E., E-mail: see3@cornell.edu. Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae. Denmark. https://doi.org/10.1107/S090744491101746X
French, Jarrod B., and Ealick, Steven E., E-mail: see3@cornell.edu. 2011. "Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae". Denmark. https://doi.org/10.1107/S090744491101746X.
@article{osti_22351238,
title = {Structural and kinetic insights into the mechanism of 5-hydroxyisourate hydrolase from Klebsiella pneumoniae},
author = {French, Jarrod B. and Ealick, Steven E., E-mail: see3@cornell.edu},
abstractNote = {The crystal structure of 5-hydroxyisourate hydrolase from K. pneumoniae and the steady-state kinetic parameters of the native enzyme as well as several mutants provide insights into the catalytic mechanism of this enzyme and the possible roles of the active-site residues. 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.},
doi = {10.1107/S090744491101746X},
url = {https://www.osti.gov/biblio/22351238}, journal = {Acta Crystallographica. Section D: Biological Crystallography},
issn = {0907-4449},
number = Pt 8,
volume = 67,
place = {Denmark},
year = {Mon Aug 01 00:00:00 EDT 2011},
month = {Mon Aug 01 00:00:00 EDT 2011}
}