1tmx

From Proteopedia

proteopedia linkproteopedia link

spinqualitylabelsall models 1tmx, resolution 1.75Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of hydroxyquinol 1,2-dioxygenase from Nocardioides Simplex 3E

Overview

Hydroxyquinol 1,2-dioxygenase (1,2-HQD) catalyzes the ring cleavage of, hydroxyquinol (1,2,4-trihydroxybenzene), a central intermediate in the, degradation of aromatic compounds including a variety of particularly, recalcitrant polychloro- and nitroaromatic pollutants. We report here the, primary sequence determination and the analysis of the crystal structure, of the 1,2-HQD from Nocardioides simplex 3E solved at 1.75 A resolution, using the multiple wavelength anomalous dispersion of the two catalytic, irons (1 Fe/293 amino acids). The catalytic Fe(III) coordination, polyhedron composed by the side chains of Tyr164, Tyr197, His221, and, His223 resembles that of the other known intradiol-cleaving dioxygenases, but several of the tertiary structure features are notably different. One, of the most distinctive characteristics of the present structure is the, extensive openings and consequent exposure to solvent of the upper part of, the catalytic cavity arranged to favor the binding of hydroxyquinols but, not catechols. A co-crystallized benzoate-like molecule is also found, bound to the metal center forming a distinctive hydrogen bond network as, observed previously also in 4-chlorocatechol 1,2-dioxygenase from, Rhodococcus opacus 1CP. This is the first structure of an intradiol, dioxygenase specialized in hydroxyquinol ring cleavage to be investigated, in detail.

About this Structure

1TMX is a Single protein structure of sequence from Pimelobacter simplex with FE, CU, CL, SO4, HGX and BEZ as ligands. Active as Hydroxyquinol 1,2-dioxygenase, with EC number 1.13.11.37 Full crystallographic information is available from OCA.

Reference

Crystal structure of the hydroxyquinol 1,2-dioxygenase from Nocardioides simplex 3E, a key enzyme involved in polychlorinated aromatics biodegradation., Ferraroni M, Seifert J, Travkin VM, Thiel M, Kaschabek S, Scozzafava A, Golovleva L, Schlomann M, Briganti F, J Biol Chem. 2005 Jun 3;280(22):21144-54. Epub 2005 Mar 16. PMID:15772073

Page seeded by OCA on Wed Nov 21 03:25:14 2007