4E9X

Multicopper Oxidase mgLAC (data3)

4E9X の概要

• エントリーDOI: 10.2210/pdb4e9x/pdb
• 関連するPDBエントリー: 4E9V 4E9W 4E9Y
• 分子名称: Multicopper oxidase, COPPER (II) ION, OXYGEN MOLECULE, ... (5 entities in total)
• 機能のキーワード: multicopper oxidase, metal binding protein
• 由来する生物種: uncultured bacterium
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 115478.69

構造登録者

Komori, H.,Miyazaki, K.,Higuchi, Y. (登録日: 2012-03-21, 公開日: 2013-03-27, 最終更新日: 2024-03-20)

主引用文献

Komori, H.,Sugiyama, R.,Kataoka, K.,Miyazaki, K.,Higuchi, Y.,Sakurai, T.
New insights into the catalytic active-site structure of multicopper oxidases.
Acta Crystallogr.,Sect.D, 70:772-779, 2014

PubMed Abstract: Structural models determined by X-ray crystallography play a central role in understanding the catalytic mechanism of enzymes. However, X-ray radiation generates hydrated electrons that can cause significant damage to the active sites of metalloenzymes. In the present study, crystal structures of the multicopper oxidases (MCOs) CueO from Escherichia coli and laccase from a metagenome were determined. Diffraction data were obtained from a single crystal under low to high X-ray dose conditions. At low levels of X-ray exposure, unambiguous electron density for an O atom was observed inside the trinuclear copper centre (TNC) in both MCOs. The gradual reduction of copper by hydrated electrons monitored by measurement of the Cu K-edge X-ray absorption spectra led to the disappearance of the electron density for the O atom. In addition, the size of the copper triangle was enlarged by a two-step shift in the location of the type III coppers owing to reduction. Further, binding of O2 to the TNC after its full reduction was observed in the case of the laccase. Based on these novel structural findings, the diverse resting structures of the MCOs and their four-electron O2-reduction process are discussed.

PubMed: 24598746
DOI: 10.1107/S1399004713033051

実験手法

X-RAY DIFFRACTION (1.14 Å)