7LJS

Porcine Dihydropyrimidine dehydrogenase (DPD) complexed with 5-Ethynyluracil (5EU) - Open Form

7LJS の概要

• エントリーDOI: 10.2210/pdb7ljs/pdb
• 分子名称: Dihydropyrimidine dehydrogenase [NADP(+)], IRON/SULFUR CLUSTER, FLAVIN MONONUCLEOTIDE, ... (6 entities in total)
• 機能のキーワード: dihydropyrimidine dehydrogenase, dpd, dehydrogenase, 5-ethynyluracil, 5eu, inhibitor, inactivator, flavoprotein
• 由来する生物種: Sus scrofa (Pig)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 457551.62

構造登録者

Butrin, A.,Forouzesh, D.,Beaupre, B.,Wawrzak, Z.,Liu, D.,Moran, G. (登録日: 2021-01-30, 公開日: 2021-04-07, 最終更新日: 2023-10-18)

主引用文献

Forouzesh, D.C.,Beaupre, B.A.,Butrin, A.,Wawrzak, Z.,Liu, D.,Moran, G.R.
The Interaction of Porcine Dihydropyrimidine Dehydrogenase with the Chemotherapy Sensitizer: 5-Ethynyluracil.
Biochemistry, 60:1120-1132, 2021

PubMed Abstract: Dihydropyrimidine dehydrogenase (DPD) is a complex enzyme that reduces the 5,6-vinylic bond of pyrimidines, uracil, and thymine. 5-Fluorouracil (5FU) is also a substrate for DPD and a common chemotherapeutic agent used to treat numerous cancers. The reduction of 5FU to 5-fluoro-5,6-dihydrouracil negates its toxicity and efficacy. Patients with high DPD activity levels typically have poor outcomes when treated with 5FU. DPD is thus a central mitigating factor in the treatment of a variety of cancers. 5-Ethynyluracil (5EU) covalently inactivates DPD by cross-linking with the active-site general acid cysteine in the pyrimidine binding site. This reaction is dependent on the simultaneous binding of 5EU and nicotinamide adenine dinucleotide phosphate (NADPH). This ternary complex induces DPD to become activated by taking up two electrons from the NADPH. The covalent inactivation of DPD by 5EU occurs concomitantly with this reductive activation with a rate constant of ∼0.2 s. This value is correlated with the rate of reduction of one of the two flavin cofactors and the localization of a mobile loop in the pyrimidine active site that places the cysteine that serves as the general acid in catalysis proximal to the 5EU ethynyl group. Efficient cross-linking is reliant on enzyme activation, but this process appears to also have a conformational aspect in that nonreductive NADPH analogues can also induce a partial inactivation. Cross-linking then renders DPD inactive by severing the proton-coupled electron transfer mechanism that transmits electrons 56 Å across the protein.

PubMed: 33755421
DOI: 10.1021/acs.biochem.1c00096

実験手法

X-RAY DIFFRACTION (2 Å)