1EHF

CRYSTAL STRUCTURES OF CYTOCHROME P450NOR AND ITS MUTANTS (SER286 VAL, THR) IN THE FERRIC RESTING STATE AT CRYOGENIC TEMPERATURE: A COMPARATIVE ANALYSIS WITH MONOOXYGENASE CYTOCHROME P450S

1EHF の概要

• エントリーDOI: 10.2210/pdb1ehf/pdb
• 関連するPDBエントリー: 1EHE 1EHG
• 分子名称: CYTOCHROME P450NOR, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• 機能のキーワード: nitric oxide reductase, cytochrome p450nor, oxidoreductase
• 由来する生物種: Fusarium oxysporum
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 45051.20

構造登録者

Shimizu, H.,Park, S. (登録日: 2000-02-21, 公開日: 2000-08-21, 最終更新日: 2024-02-07)

主引用文献

Shimizu, H.,Park, S.,Lee, D.,Shoun, H.,Shiro, Y.
Crystal structures of cytochrome P450nor and its mutants (Ser286-->Val, Thr) in the ferric resting state at cryogenic temperature: a comparative analysis with monooxygenase cytochrome P450s.
J.Inorg.Biochem., 81:191-205, 2000

PubMed Abstract: Cytochrome P450nor (P450nor) is a heme enzyme isolated from the denitrifying fungus Fusarium oxysporum and catalyzes the NO reduction to N2O. Crystal structures of the wild type and two Ser286 mutants (Ser286-->Val, Ser286-->Thr) of P450nor have been determined for the ferric resting forms at a 1.7 A resolution at cryogenic temperature (100 K). We carried out three comparative analyses: (1) between the structures of P450nor at room temperature and cryogenic temperature, (2) between the structures of P450nor and four monooxygenase P450s, and (3) between the structures of the WT and the Ser286 mutant enzymes of P450nor. Comparison of the charge distribution on the protein surface suggests that proton and electron flow to the heme site is quite different in P450nor than in monooxygenase P450s. On the basis of the mutant structures, it was found that a special hydrogen-bonding network, Wat99-Ser286-Wat39-Asp393-solvent, acts as a proton delivery pathway in NO reduction by P450nor. In addition, the positively charged cluster located beneath the B'-helix is suggested as possible NADH binding site in P450nor, from which the direct two-electron transfer to the heme site allows to generate the characteristic intermediate in the NO reduction. These structural characteristics were not observed in structures of monooxygenase P450s, implying that these are factors determining the unique NO reduction activity of P450nor.

PubMed: 11051564
DOI: 10.1016/S0162-0134(00)00103-3

実験手法

X-RAY DIFFRACTION (1.7 Å)