Subunit Arrangement of a 2-Ketoisovalerate Ferredoxin Oxidoreductase from Thermococcus profundus Revealed by a Low Resolution X-Ray Analysis
Subunit Arrangement of a 2-Ketoisovalerate Ferredoxin Oxidoreductase from Thermococcus profundus Revealed by a Low Resolution X-Ray Analysis作者机构:Department of Life Science and Graduate School of Life Science Rikkyo (St. Paul’s) University Tokyo Japan Photosynthesis Research Center Okayama University Okayama Japan Research Reactor Institute Kyoto University Osaka Japan
出 版 物:《Advances in Enzyme Research》 (酶研究进展(英文))
年 卷 期:2015年第3卷第3期
页 面:75-80页
学科分类:1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学]
主 题:Oxidoreductase X-Ray Analysis Iron-Sulfur Cluster
摘 要:2-ketoisovalerate ferredoxin oxidoreductase (VOR) is a key enzyme in hyperthermophiles catalyzing the coenzyme A-dependent oxidative decarboxylation of aliphatic amino acid-derived 2-keto acids. The enzyme purified under anaerobic conditions from a hyperthermophilic archaeon, Thermococcus profundus, is a hetero-octamer (αβγδ)2 consisting of four different subunits, α = 45 kDa, β = 31 kDa, γ = 22 kDa and δ = 13 kDa, respectively, and it has three [4Fe-4S] clusters per αβγδ-protomer, similar to other ferredoxin oxidoreductases. In the present study, the native enzyme was purified from this strain and crystallized to give rod-like crystals that were suitable for X-ray diffraction experiments. The crystals belonged to space group P41212, with unit-cell parameters a = b = 136.20 ?, c = 221.07 ?. Diffraction images were processed to a resolution of 3.0 ?. The data collected so far indicate the approximate molecular boundaries and a partial main-chain trace of the enzyme.