1qh3
From Proteopedia
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, resolution 1.9Å | |||||||
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Ligands: | , , , , | ||||||
Activity: | Hydroxyacylglutathione hydrolase, with EC number 3.1.2.6 | ||||||
Related: | 1QH5
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Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
Coordinates: | save as pdb, mmCIF, xml |
HUMAN GLYOXALASE II WITH CACODYLATE AND ACETATE IONS PRESENT IN THE ACTIVE SITE
Overview
BACKGROUND: Glyoxalase II, the second of two enzymes in the glyoxalase system, is a thiolesterase that catalyses the hydrolysis of S-D-lactoylglutathione to form glutathione and D-lactic acid. RESULTS: The structure of human glyoxalase II was solved initially by single isomorphous replacement with anomalous scattering and refined at a resolution of 1.9 A. The enzyme consists of two domains. The first domain folds into a four-layered beta sandwich, similar to that seen in the metallo-beta-lactamases. The second domain is predominantly alpha-helical. The active site contains a binuclear zinc-binding site and a substrate-binding site extending over the domain interface. The model contains acetate and cacodylate in the active site. A second complex was derived from crystals soaked in a solution containing the slow substrate, S-(N-hydroxy-N-bromophenylcarbamoyl)glutathione. This complex was refined at a resolution of 1.45 A. It contains the added ligand in one molecule of the asymmetric unit and glutathione in the other. CONCLUSIONS: The arrangement of ligands around the zinc ions includes a water molecule, presumably in the form of a hydroxide ion, coordinated to both metal ions. This hydroxide ion is situated 2.9 A from the carbonyl carbon of the substrate in such a position that it could act as the nucleophile during catalysis. The reaction mechanism may also have implications for the action of metallo-beta-lactamases.
About this Structure
1QH3 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of human glyoxalase II and its complex with a glutathione thiolester substrate analogue., Cameron AD, Ridderstrom M, Olin B, Mannervik B, Structure. 1999 Sep 15;7(9):1067-78. PMID:10508780
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