2imd

Structure of SeMet 2-hydroxychromene-2-carboxylate isomerase (HCCA isomerase)Structure of SeMet 2-hydroxychromene-2-carboxylate isomerase (HCCA isomerase)

Structural highlights 2imd is a 1 chain structure with sequence from "bacillus_fluorescens_putidus"_flugge_1886 "bacillus fluorescens putidus" flugge 1886. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: , , , , NonStd Res: Related: 1r4w, 2ime, 2imf Gene: nahD ("Bacillus fluorescens putidus" Flugge 1886) Activity: Glutathione transferase, with EC number 2.5.1.18 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [NAHD_PSEPU] Involved in the naphthalene catabolic pathway. Catalyzes the reversible glutathione-dependent isomerization of 2-hydroxychromene-2-carboxylate (HCCA) to trans-O-hydroxybenzylidenepyruvate (THBPA). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The enzyme 2-hydroxychromene-2-carboxylic acid (HCCA) isomerase catalyzes the glutathione (GSH)-dependent interconversion (Keq = 1.5) of HCCA and trans-o-hydroxybenzylidene pyruvic acid (tHBPA) in the naphthalene catabolic pathway of Pseudomonas putida. The dimeric protein binds one molecule of GSH very tightly (Kd approximately 5 nM) and a second molecule of GSH with much lower affinity (Kd approximately 2 to 11 microM). The enzyme is unstable in the absence of GSH. The turnover number in the forward direction (47 s(-1) at 25 degrees C) greatly exceeds off rates for GSH (koff approximately 10(-3) to 10(-2) s(-1) at 10 degrees C), suggesting that GSH acts as a tightly bound cofactor in the reaction. The crystal structure of the enzyme at 1.7 A resolution reveals that the isomerase is closely related to class kappa GSH transferases. Diffraction quality crystals could only be obtained in the presence of GSH and HCCA/tHBPA. Clear electron density is seen for GSH. Electron density for the organic substrates is located near the GSH and is best modeled to include both HCCA and tHBPA at occupancies of 0.5 for each. Although there is no electron density connecting the sulfur of GSH to the organic substrates, the sulfur is located very close (2.78 A) to C7 of HCCA. Taken together, the results suggest that the isomerization reaction involves a short-lived covalent adduct between the sulfur of GSH and C7 of the substrate. 2-Hydroxychromene-2-carboxylic acid isomerase: a kappa class glutathione transferase from Pseudomonas putida.,Thompson LC, Ladner JE, Codreanu SG, Harp J, Gilliland GL, Armstrong RN Biochemistry. 2007 Jun 12;46(23):6710-22. Epub 2007 May 18. PMID:17508726 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 2imd, resolution 1.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image