The symbiotically essential cbb3-type oxidase of Bradyrhizobium japonicum is a proton pump

被引：43

作者：

Arslan, E

Kannt, A

Thöny-Meyer, L

Hennecke, H

机构：

[1] Swiss Fed Inst Technol, Inst Mikrobiol, CH-8092 Zurich, Switzerland

[2] Max Planck Inst Biophys, Abt Mol Membranbiol, D-60528 Frankfurt, Germany

来源：

FEBS LETTERS | 2000年 / 470卷 / 01期

关键词：

Bradyrhizobium japonicum; cbb(3)-type oxidase; cytochrome c oxidase; nitrogen fixation; proton pumping;

D O I：

10.1016/S0014-5793(00)01277-1

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Purified cbb(3)-type oxidase of Bradyvhizobirrmjapo-nicum was reconstituted into phospholipid vesicles. Tight vesicles were obtained as shown by the disturbance of Delta pH with CCCP and the membrane potential with valinomycin, which led to a sixfold increase in cytochrome c oxidase activity. The vesicles were thus suitable for proton translocation experiments. In the presence of valinomycin, a pulse with reduced cytochrome c caused an acidification with a subsequent alkalinization, whereas the same pulse caused only an alkalinization in the presence of valinomycin plus CCCP. We conclude that the cbb(3)-type oxidase of B. japonicum is a proton pump. (C) 2000 Federation of European Biochemical Societies.

引用

页码：7 / 10

页数：4

共 34 条

[1] GENES FOR A 2ND TERMINAL OXIDASE IN BRADYRHIZOBIUM-JAPONICUM [J].