5OC0

Structure of E. coli superoxide oxidase

5OC0 の概要

• エントリーDOI: 10.2210/pdb5oc0/pdb
• 分子名称: Cytochrome b561, PROTOPORPHYRIN IX CONTAINING FE, MAGNESIUM ION, ... (6 entities in total)
• 機能のキーワード: membrane protein, superoxide, electron transport, heme, respiratory chain, ros, quinone, ubiquinone, oxidoreductase
• 由来する生物種: Escherichia coli K12
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 24278.98

構造登録者

Lundgren, C.A.K.,Sjostrand, D.,Biner, O.,Bennett, M.,von Ballmoos, C.,Hogbom, M. (登録日: 2017-06-29, 公開日: 2018-06-20, 最終更新日: 2024-11-06)

主引用文献

Lundgren, C.A.K.,Sjostrand, D.,Biner, O.,Bennett, M.,Rudling, A.,Johansson, A.L.,Brzezinski, P.,Carlsson, J.,von Ballmoos, C.,Hogbom, M.
Scavenging of superoxide by a membrane-bound superoxide oxidase.
Nat. Chem. Biol., 14:788-793, 2018

PubMed Abstract: Superoxide is a reactive oxygen species produced during aerobic metabolism in mitochondria and prokaryotes. It causes damage to lipids, proteins and DNA and is implicated in cancer, cardiovascular disease, neurodegenerative disorders and aging. As protection, cells express soluble superoxide dismutases, disproportionating superoxide to oxygen and hydrogen peroxide. Here, we describe a membrane-bound enzyme that directly oxidizes superoxide and funnels the sequestered electrons to ubiquinone in a diffusion-limited reaction. Experiments in proteoliposomes and inverted membranes show that the protein is capable of efficiently quenching superoxide generated at the membrane in vitro. The 2.0 Å crystal structure shows an integral membrane di-heme cytochrome b poised for electron transfer from the P-side and proton uptake from the N-side. This suggests that the reaction is electrogenic and contributes to the membrane potential while also conserving energy by reducing the quinone pool. Based on this enzymatic activity, we propose that the enzyme family be denoted superoxide oxidase (SOO).

PubMed: 29915379
DOI: 10.1038/s41589-018-0072-x

実験手法

X-RAY DIFFRACTION (1.97 Å)