1P9E

Crystal Structure Analysis of Methyl Parathion Hydrolase from Pseudomonas sp WBC-3

1P9E の概要

• エントリーDOI: 10.2210/pdb1p9e/pdb
• 分子名称: Methyl Parathion Hydrolase, ZINC ION, POTASSIUM ION, ... (6 entities in total)
• 機能のキーワード: zn containing, hydrolase
• 由来する生物種: Pseudomonas sp.
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 70443.69

構造登録者

Dong, Y.,Sun, L.,Bartlam, M.,Rao, Z.,Zhang, X. (登録日: 2003-05-11, 公開日: 2004-05-25, 最終更新日: 2024-12-04)

主引用文献

Dong, Y.J.,Bartlam, M.,Sun, L.,Zhou, Y.F.,Zhang, Z.P.,Zhang, C.G.,Rao, Z.,Zhang, X.E.
Crystal structure of methyl parathion hydrolase from Pseudomonas sp. WBC-3.
J.Mol.Biol., 353:655-663, 2005

PubMed Abstract: Methyl parathion hydrolase (MPH, E.C.3.1.8.1), isolated from the soil-dwelling bacterium Pseudomonas sp. WBC-3, is a Zn(II)-containing enzyme that catalyzes the degradation of the organophosphate pesticide methyl parathion. We have determined the structure of MPH from Pseudomonas sp. WBC-3 to 2.4 angstroms resolution. The enzyme is dimeric and each subunit contains a mixed hybrid binuclear zinc center, in which one of the zinc ions is replaced by cadmium. In both subunits, the more solvent-exposed beta-metal ion is substituted for Cd2+ due to high cadmium concentration in the crystallization condition. Both ions are surrounded by ligands in an octahedral arrangement. The ions are separated by 3.5 angstroms and are coordinated by the amino acid residues His147, His149, Asp151, His152, His234 and His302 and a water molecule. Asp255 and a water molecule serve to bridge the zinc ions together. MPH is homologous with other metallo-beta-lactamases but does not show any similarity to phosphotriesterase that can also catalyze the degradation of methyl parathion with lower rate, despite the lack of sequence homology. Trp179, Phe196 and Phe119 form an aromatic cluster at the entrance of the catalytic center. Replacement of these three amino acids by alanine resulted in a significant increase of K(m) and loss of catalytic activity, indicating that the aromatic cluster has an important role to facilitate affinity of enzyme to the methyl parathion substrates.

PubMed: 16181636
DOI: 10.1016/j.jmb.2005.08.057

実験手法

X-RAY DIFFRACTION (2.4 Å)