1V97

Crystal Structure of Bovine Milk Xanthine Dehydrogenase FYX-051 bound form

1V97 の概要

• エントリーDOI: 10.2210/pdb1v97/pdb
• 分子名称: Xanthine dehydrogenase, CALCIUM ION, FE2/S2 (INORGANIC) CLUSTER, ... (10 entities in total)
• 機能のキーワード: xanthine dehydrogenase, molybdopterin, fyx-051, reaction intermediate, oxidoreductase
• 由来する生物種: Bos taurus (cattle)
• 細胞内の位置: Cytoplasm (By similarity): P80457
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 298806.89

構造登録者

Okamoto, K.,Matsumoto, K.,Hille, R.,Eger, B.T.,Pai, E.F.,Nishino, T. (登録日: 2004-01-21, 公開日: 2004-06-22, 最終更新日: 2023-12-27)

主引用文献

Okamoto, K.,Matsumoto, K.,Hille, R.,Eger, B.T.,Pai, E.F.,Nishino, T.
The crystal structure of xanthine oxidoreductase during catalysis: Implications for reaction mechanism and enzyme inhibition.
Proc.Natl.Acad.Sci.USA, 101:7931-7936, 2004

PubMed Abstract: Molybdenum is widely distributed in biology and is usually found as a mononuclear metal center in the active sites of many enzymes catalyzing oxygen atom transfer. The molybdenum hydroxylases are distinct from other biological systems catalyzing hydroxylation reactions in that the oxygen atom incorporated into the product is derived from water rather than molecular oxygen. Here, we present the crystal structure of the key intermediate in the hydroxylation reaction of xanthine oxidoreductase with a slow substrate, in which the carbon-oxygen bond of the product is formed, yet the product remains complexed to the molybdenum. This intermediate displays a stable broad charge-transfer band at approximately 640 nm. The crystal structure of the complex indicates that the catalytically labile Mo-OH oxygen has formed a bond with a carbon atom of the substrate. In addition, the MoS group of the oxidized enzyme has become protonated to afford Mo-SH on reduction of the molybdenum center. In contrast to previous assignments, we find this last ligand at an equatorial position in the square-pyramidal metal coordination sphere, not the apical position. A water molecule usually seen in the active site of the enzyme is absent in the present structure, which probably accounts for the stability of this intermediate toward ligand displacement by hydroxide.

PubMed: 15148401
DOI: 10.1073/pnas.0400973101

実験手法

X-RAY DIFFRACTION (1.94 Å)