1mpy

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spinqualitylabelsall models 1mpy, resolution 2.8Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

STRUCTURE OF CATECHOL 2,3-DIOXYGENASE (METAPYROCATECHASE) FROM PSEUDOMONAS PUTIDA MT-2

Overview

BACKGROUND: Catechol dioxygenases catalyze the ring cleavage of catechol, and its derivatives in either an intradiol or extradiol manner. These, enzymes have a key role in the degradation of aromatic molecules in the, environment by soil bacteria. Catechol 2, 3-dioxygenase catalyzes the, incorporation of dioxygen into catechol and the extradiol ring cleavage to, form 2-hydroxymuconate semialdehyde. Catechol 2,3-dioxygenase, (metapyrocatechase, MPC) from Pseudomonas putida mt-2 was the first, extradiol dioxygenase to be obtained in a pure form and has been studied, extensively. The lack of an MPC structure has hampered the understanding, of the general mechanism of extradiol dioxygenases. RESULTS: The, three-dimensional structure of MPC has been determined at 2.8 A resolution, by the multiple isomorphous replacement method. The enzyme is a, homotetramer with each subunit folded into two similar domains. The, structure of the MPC subunit resembles that of 2,3-dihydroxybiphenyl, 1,2-dioxygenase, although there is low amino acid sequence identity, between these enzymes. The active-site structure reveals a distorted, tetrahedral Fe(II) site with three endogenous ligands (His153, His214 and, Glu265), and an additional molecule that is most probably acetone., CONCLUSIONS: The present structure of MPC, combined with those of two, 2,3-dihydroxybiphenyl 1,2-dioxygenases, reveals a conserved core region of, the active site comprising three Fe(II) ligands (His153, His214 and, Glu265), one tyrosine (Tyr255) and two histidine (His199 and His246), residues. The results suggest that extradiol dioxygenases employ a common, mechanism to recognize the catechol ring moiety of various substrates and, to activate dioxygen. One of the conserved histidine residues (His199), seems to have important roles in the catalytic cycle.

About this Structure

1MPY is a Single protein structure of sequence from Pseudomonas putida with FE2 and ACN as ligands. Active as Catechol 2,3-dioxygenase, with EC number 1.13.11.2 Full crystallographic information is available from OCA.

Reference

An archetypical extradiol-cleaving catecholic dioxygenase: the crystal structure of catechol 2,3-dioxygenase (metapyrocatechase) from Ppseudomonas putida mt-2., Kita A, Kita S, Fujisawa I, Inaka K, Ishida T, Horiike K, Nozaki M, Miki K, Structure. 1999 Jan 15;7(1):25-34. PMID:10368270

Page seeded by OCA on Tue Nov 20 21:37:32 2007