1dub

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spinqualitylabelsall models 1dub, resolution 2.5Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

2-ENOYL-COA HYDRATASE, DATA COLLECTED AT 100 K, PH 6.5

Overview

The crystal structure of rat liver mitochondrial enoyl-coenzyme A (CoA), hydratase complexed with the potent inhibitor acetoacetyl-CoA has been, refined at 2.5 angstroms resolution. This enzyme catalyses the reversible, addition of water to alpha,beta-unsaturated enoyl-CoA thioesters, with, nearly diffusion-controlled reaction rates for the best substrates., Enoyl-CoA hydratase is a hexamer of six identical subunits of 161 kDa, molecular mass for the complex. The hexamer is a dimer of trimers. The, monomer is folded into a right-handed spiral of four turns, followed by, two small domains which are involved in trimerization. Each turn of the, spiral consists of two beta-strands and an alpha-helix. The mechanism for, the hydratase/dehydratase reaction follows a syn-stereochemistry, a, preference that is opposite to the nonenzymatic reaction. The active-site, architecture agrees with this stereochemistry. It confirms the importance, of Glu164 as the catalytic acid for providing the alpha-proton during the, hydratase reaction. It also shows the importance of Glu144 as the, catalytic base for the activation of a water molecule in the hydratase, reaction. The comparison of an unliganded and a liganded active site, within the same crystal form shows a water molecule in the unliganded, subunit. This water molecule is bound between the two catalytic glutamates, and could serve as the activated water during catalysis.

About this Structure

1DUB is a Single protein structure of sequence from Rattus norvegicus with CAA as ligand. Active as Enoyl-CoA hydratase, with EC number 4.2.1.17 Known structural/functional Sites: and . Full crystallographic information is available from OCA.

Reference

Crystal structure of enoyl-coenzyme A (CoA) hydratase at 2.5 angstroms resolution: a spiral fold defines the CoA-binding pocket., Engel CK, Mathieu M, Zeelen JP, Hiltunen JK, Wierenga RK, EMBO J. 1996 Oct 1;15(19):5135-45. PMID:8895557

Page seeded by OCA on Tue Dec 18 14:45:15 2007