2QFK

X-ray Crystal Structure Analysis of the Binding Site in the Ferric and Oxyferrous Forms of the Recombinant Heme Dehaloperoxidase Cloned from Amphitrite ornata

2QFK の概要

• エントリーDOI: 10.2210/pdb2qfk/pdb
• 関連するPDBエントリー: 2QFN
• 分子名称: Dehaloperoxidase A, AMMONIUM ION, SULFATE ION, ... (5 entities in total)
• 機能のキーワード: crystal structure of dehaloperoxidase, dhp, globin, heme protein, transport protein
• 由来する生物種: Amphitrite ornata
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 32672.47

構造登録者

de Serrano, V.S.,Chen, Z.,Davis, M.F.,Franzen, S. (登録日: 2007-06-27, 公開日: 2008-07-08, 最終更新日: 2024-02-21)

主引用文献

de Serrano, V.S.,Chen, Z.,Davis, M.F.,Franzen, S.
X-ray crystal structural analysis of the binding site in the ferric and oxyferrous forms of the recombinant heme dehaloperoxidase cloned from Amphitrite ornata
Acta Crystallogr.,Sect.D, 63:1094-1101, 2007

PubMed Abstract: The dehaloperoxidase (DHP) from the terebellid polychaete Amphitrite ornata is an enzyme that converts para-halogenated phenols to the corresponding quinones in the presence of hydrogen peroxide. Its enzymatic activity is similar to that of heme peroxidases such as horseradish peroxidase, yet it has the structural characteristics of the globin family of proteins, the main functions of which are oxygen transport and storage. In order to investigate the dual function of this hemoglobin peroxidase, the enzyme was expressed in Escherichia coli as a recombinant protein in its wild-type form and as a mutant protein in which Cys73 was replaced by a serine residue (C73S). Both the wild-type and mutant proteins were crystallized and their structures were determined at 100 K to a resolution of 1.62 A. The structure of the wild-type protein demonstrated that it was in the metaquo form, with the heme iron in the ferric oxidation state and the bound water lying 2.2 A from the heme iron. The structure of the C73S mutant protein was shown to contain a ferrous heme iron with a bound oxygen molecule. The bent bonding geometry of the Fe-O(1)-O(2) adduct results in a hydrogen bond of length 2.8 A between the second O atom, O(2), of molecular oxygen and N(2) of the distal histidine residue (His55) in both subunits contained within the asymmetric unit. This hydrogen-bonding interaction between His55 and the bound diatomic oxygen molecule provides new insight into the catalytic activation of H(2)O(2), which is essential for peroxidase activity.

PubMed: 17881827
DOI: 10.1107/S0907444907043417

実験手法

X-RAY DIFFRACTION (1.62 Å)