1m6w

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spinqualitylabelsall models 1m6w, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Binary complex of Human glutathione-dependent formaldehyde dehydrogenase and 12-Hydroxydodecanoic acid

Overview

The human glutathione-dependent formaldehyde dehydrogenase is unique among, the structurally studied members of the alcohol dehydrogenase family in, that it follows a random bi bi kinetic mechanism. The structures of an apo, form of the enzyme, a binary complex with substrate 12-hydroxydodecanoic, acid, and a ternary complex with NAD+ and the inhibitor dodecanoic acid, were determined at 2.0, 2.3, and 2.3 A resolution by X-ray crystallography, using the anomalous diffraction signal of zinc. The structures of the, enzyme and its binary complex with the primary alcohol substrate, 12-hydroxydodecanoic acid, and the previously reported binary complex with, the coenzyme show that the binding of the first substrate (alcohol or, coenzyme) causes only minor changes to the overall structure of the, enzyme. This is consistent with the random mechanism of the enzyme where, either of the substrates binds to the free enzyme. The catalytic-domain, position in these structures is intermediate to the "closed" and "open", conformations observed in class I alcohol dehydrogenases. More, importantly, two different tetrahedral coordination environments of the, active site zinc are observed in these structures. In the apoenzyme, the, active site zinc is coordinated to Cys44, His66 and Cys173, and a water, molecule. In the inhibitor complex, the coordination environment involves, Glu67 instead of the solvent water molecule. The coordination environment, involving Glu67 as the fourth ligand likely represents an intermediate, step during ligand exchange at the active site zinc. These observations, provide new insight into metal-assisted catalysis and substrate binding in, glutathione-dependent formaldehyde dehydrogenase.

About this Structure

1M6W is a Single protein structure of sequence from Homo sapiens with ZN, K, PO4 and 12H as ligands. Active as Alcohol dehydrogenase, with EC number 1.1.1.1 Full crystallographic information is available from OCA.

Reference

Human glutathione-dependent formaldehyde dehydrogenase. Structures of apo, binary, and inhibitory ternary complexes., Sanghani PC, Robinson H, Bosron WF, Hurley TD, Biochemistry. 2002 Sep 3;41(35):10778-86. PMID:12196016

Page seeded by OCA on Mon Nov 12 18:08:17 2007