1qh5
From Proteopedia
HUMAN GLYOXALASE II WITH S-(N-HYDROXY-N-BROMOPHENYLCARBAMOYL)GLUTATHIONE
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
1QH5 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 Page seeded by OCA on Sat May 3 06:15:55 2008
