2ZAF

Mechanistic and Structural Analyses of the Roles of Arg409 and Asp402 in the Reaction of the Flavoprotein Nitroalkane Oxidase

2ZAF の概要

• エントリーDOI: 10.2210/pdb2zaf/pdb
• 関連するPDBエントリー: 2C0U 2C12 2REH
• 分子名称: Nitroalkane oxidase, FLAVIN-ADENINE DINUCLEOTIDE (2 entities in total)
• 機能のキーワード: oxidoreductase, flavoenzyme, nitroalkane, flavoprotein
• 由来する生物種: Fusarium oxysporum
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 195907.12

構造登録者

Fitzpatrick, P.F.,Bozinovski, D.M.,Heroux, A.,Shaw, P.G.,Valley, M.P.,Orville, A.M. (登録日: 2007-10-05, 公開日: 2008-06-03, 最終更新日: 2023-11-01)

主引用文献

Fitzpatrick, P.F.,Bozinovski, D.M.,Heroux, A.,Shaw, P.G.,Valley, M.P.,Orville, A.M.
Mechanistic and structural analyses of the roles of Arg409 and Asp402 in the reaction of the flavoprotein nitroalkane oxidase.
Biochemistry, 46:13800-13808, 2007

PubMed Abstract: The flavoprotein nitroalkane oxidase (NAO) catalyzes the oxidation of primary and secondary nitroalkanes to the corresponding aldehydes and ketones. The enzyme is a homologue of acyl-CoA dehydrogenase. Asp402 in NAO has been proposed to be the active site base responsible for removing the substrate proton in the first catalytic step; structurally it corresponds to the glutamate which acts as the base in medium chain acyl-CoA dehydrogenase. In the active site of NAO, the carboxylate of Asp402 forms an ionic interaction with the side chain of Arg409. The R409K enzyme has now been characterized kinetically and structurally. The mutation results in a decrease in the rate constant for proton abstraction of 100-fold. Analysis of the three-dimensional structure of the R409K enzyme, determined by X-ray crystallography to a resolution of 2.65 A, shows that the critical structural change is an increase in the distance between the carboxylate of Asp402 and the positively charged nitrogen in the side chain of the residue at position 409. The D402E mutation results in a smaller decrease in the rate constant for proton abstraction of 18-fold. The structure of the D402E enzyme, determined at 2.4 A resolution, shows that there is a smaller increase in the distance between Arg409 and the carboxylate at position 402, and the interaction of this residue with Ser276 is perturbed. These results establish the critical importance of the interaction between Asp402 and Arg409 for proton abstraction by nitroalkane oxidase.

PubMed: 17994768
DOI: 10.1021/bi701557k

実験手法

X-RAY DIFFRACTION (2.5 Å)