2IH8

A low-dose crystal structure of a recombinant Melanocarpus albomyces laccase

2IH8 の概要

• エントリーDOI: 10.2210/pdb2ih8/pdb
• 関連するPDBエントリー: 1GW0 2IH9
• 分子名称: Laccase-1, OXYGEN MOLECULE, alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (11 entities in total)
• 機能のキーワード: laccase, multicopper oxidase, redox-enzyme, oxidoreductase
• 由来する生物種: Melanocarpus albomyces
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 130863.13

構造登録者

Hakulinen, N.,Rouvinen, J. (登録日: 2006-09-26, 公開日: 2006-11-14, 最終更新日: 2024-10-30)

主引用文献

Hakulinen, N.,Kruus, K.,Koivula, A.,Rouvinen, J.
A crystallographic and spectroscopic study on the effect of X-ray radiation on the crystal structure of Melanocarpus albomyces laccase.
Biochem.Biophys.Res.Commun., 350:929-934, 2006

PubMed Abstract: Laccases (p-diphenol dioxygen oxidoreductases) belong to the family of blue multicopper oxidases, which catalyse the four-electron reduction of dioxygen to water concomitantly through the oxidation of substrate molecules. Blue multicopper oxidases have four coppers, a copper (T1) forming a mononuclear site and a cluster of three coppers (T2, T3, and T3') forming a trinuclear site. Because X-rays are known to liberate electrons during data collection and may thus affect the oxidation state of metals, we have investigated the effect of X-ray radiation upon the crystal structure of a recombinant laccase from Melanocarpus albomyces through the use of crystallography and crystal absorption spectroscopy. Two data sets with different strategies, a low and a high-dose data set, were collected at synchrotron. We have observed earlier that the trinuclear site had an elongated electron density amidst coppers, suggesting dioxygen binding. The low-dose synchrotron structure showed similar elongated electron density, but the high-dose X-ray radiation removed the bulk of this density. Therefore, X-ray radiation could alter the active site of laccase from M. albomyces. Absorption spectra of the crystals (320, 420, and 590nm) during X-ray radiation were measured at a home laboratory. Spectra clearly showed how that the band at 590nm had vanished, resulting from the T1 copper being reduced, during the long X-ray measurements. The crystal colour changed from blue to colourless. Absorptions at 320 and 420nm seemed to be rather permanent. The absorption at 320nm is due to the T3 coppers and it is proposed that absorption at 420nm is due to the T2 copper when dioxygen or a reaction intermediate is close to this copper.

PubMed: 17045575
DOI: 10.1016/j.bbrc.2006.09.144

実験手法

X-RAY DIFFRACTION (2 Å)