1QRD

QUINONE REDUCTASE/FAD/CIBACRON BLUE/DUROQUINONE COMPLEX

1QRD の概要

• エントリーDOI: 10.2210/pdb1qrd/pdb
• 分子名称: QUINONE-REDUCTASE, FLAVIN-ADENINE DINUCLEOTIDE, CIBACRON BLUE, ... (5 entities in total)
• 機能のキーワード: quinone-reductase (cytosolic), oxidoreductase, flavoprotein
• 由来する生物種: Rattus rattus (black rat)
• 細胞内の位置: Cytoplasm: P05982
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 65152.57

構造登録者

Li, R.,Bianchet, M.A.,Talalay, P.,Amzel, L.M. (登録日: 1995-07-28, 公開日: 1996-10-14, 最終更新日: 2024-02-14)

主引用文献

Li, R.,Bianchet, M.A.,Talalay, P.,Amzel, L.M.
The three-dimensional structure of NAD(P)H:quinone reductase, a flavoprotein involved in cancer chemoprotection and chemotherapy: mechanism of the two-electron reduction.
Proc.Natl.Acad.Sci.USA, 92:8846-8850, 1995

PubMed Abstract: Quinone reductase [NAD(P)H:(quinone acceptor) oxidoreductase, EC 1.6.99.2], also called DT diaphorase, is a homodimeric FAD-containing enzyme that catalyzes obligatory NAD(P)H-dependent two-electron reductions of quinones and protects cells against the toxic and neoplastic effects of free radicals and reactive oxygen species arising from one-electron reductions. These two-electron reductions participate in the reductive bioactivation of cancer chemotherapeutic agents such as mitomycin C in tumor cells. Thus, surprisingly, the same enzymatic reaction that protects normal cells activates cytotoxic drugs used in cancer chemotherapy. The 2.1-A crystal structure of rat liver quinone reductase reveals that the folding of a portion of each monomer is similar to that of flavodoxin, a bacterial FMN-containing protein. Two additional portions of the polypeptide chains are involved in dimerization and in formation of the two identical catalytic sites to which both monomers contribute. The crystallographic structures of two FAD-containing enzyme complexes (one containing NADP+, the other containing duroquinone) suggest that direct hydride transfers from NAD(P)H to FAD and from FADH2 to the quinone [which occupies the site vacated by NAD(P)H] provide a simple rationale for the obligatory two-electron reductions involving a ping-pong mechanism.

PubMed: 7568029
DOI: 10.1073/pnas.92.19.8846

実験手法

X-RAY DIFFRACTION (2.4 Å)