2CDU

The Crystal Structure of Water-forming NAD(P)H Oxidase from Lactobacillus sanfranciscensis

2CDU の概要

• エントリーDOI: 10.2210/pdb2cdu/pdb
• 分子名称: NADPH OXIDASE, FLAVIN-ADENINE DINUCLEOTIDE, ADENOSINE-5'-DIPHOSPHATE, ... (4 entities in total)
• 機能のキーワード: nad(p)h oxidase, flavoenzyme, oxidoreductase
• 由来する生物種: LACTOBACILLUS SANFRANCISCENSIS
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 101865.85

構造登録者

Lountos, G.T.,Jiang, R.,Wellborn, W.B.,Thaler, T.L.,Bommarius, A.S.,Orville, A.M. (登録日: 2006-01-28, 公開日: 2006-07-17, 最終更新日: 2024-01-31)

主引用文献

Lountos, G.T.,Jiang, R.,Wellborn, W.B.,Thaler, T.L.,Bommarius, A.S.,Orville, A.M.
The Crystal Structure of Nad(P)H Oxidase from Lactobacillus Sanfranciscensis: Insights Into the Conversion of O(2) Into Two Water Molecules by the Flavoenzyme.
Biochemistry, 45:9648-, 2006

PubMed Abstract: The FAD-dependent NAD(P)H oxidase from Lactobacillus sanfrancisensis (L.san-Nox2) catalyzes the oxidation of 2 equivalents of either NADH or NADPH and reduces 1 equivalent of O(2) to yield 2 equivalents of water. During steady-state turnover only 0.5% of the reducing equivalents are detected in solution as hydrogen peroxide, suggesting that it is not released from the enzyme after the oxidation of the first equivalent of NAD(P)H and reaction with O(2). Here we report the crystal structure of L.san-Nox2 to 1.8 A resolution. The enzyme crystallizes as a dimer with each monomer consisting of a FAD binding domain (residues 1-120), a NAD(P)H binding domain (residues 150-250), and a dimerization domain (residues 325-451). The electron density for the redox-active Cys42 residue located adjacent to the si-face FAD is consistent with oxidation to the sulfenic acid (Cys-SOH) state. The side chain of Cys42 is also observed in two conformations; in one the sulfenic acid is hydrogen bonded to His10 and in the other it hydrogen bonds with the FAD O2' atom. Surprisingly, the NAD(P)H binding domains each contain an ADP ligand as established by electron density maps and MALDI-TOF analysis of the ligands released from heat-denatured enzyme. The ADP ligand copurifies with the enzyme, and its presence does not inhibit enzyme activity. Consequently, we hypothesize that either NADPH or NADH substrates bind via a long channel that extends from the enzyme exterior and terminates at the FAD re-face. A homology model of the NADH oxidase from Lactococcus lactis (L.lac-Nox2) was also generated using the crystal structure of L.san-Nox2, which reveals several important similarities and differences between the two enzymes. HPLC analysis of ligands released from denatured L.lac-Nox2 indicates that it does not bind ADP, which correlates with the specificity of the enzyme for oxidation of NADH.

PubMed: 16893166
DOI: 10.1021/BI060692P

実験手法

X-RAY DIFFRACTION (1.8 Å)