de Hollander J A, Stouthamer A H
Eur J Biochem. 1980 Oct;111(2):473-8. doi: 10.1111/j.1432-1033.1980.tb04962.x.
The presence of a branched respiratory chain in Rhizobium trifolii grown in batch culture on a defined medium was demonstrated. The branches of the respiratory chain differ in sensitivity to inhibition by cyanide and in affinity for oxygen. The branching point is localized at cytochrome b-555. Electron flow from cytochrome b-555 via cytochrome c-549 and cytochrome a-597 towards oxygen has a relatively low affinity for oxygen and is sensitive to inhibition by cyanide. The second terminal oxidase is cytochrome b-561, which is directly linked to cytochrome b-555. This pathway has a higher affinity for oxygen. The pathway via cytochrome a-597 is more efficient in energy conservation than the pathway via cytochrome b-561, which lacks site III of oxidative phosphorylation.
已证明在限定培养基上进行分批培养的三叶草根瘤菌中存在分支呼吸链。呼吸链的分支对氰化物抑制的敏感性以及对氧气的亲和力不同。分支点定位于细胞色素b-555。从细胞色素b-555经细胞色素c-549和细胞色素a-597向氧气的电子流对氧气的亲和力相对较低，且对氰化物抑制敏感。第二个末端氧化酶是细胞色素b-561，它直接与细胞色素b-555相连。该途径对氧气具有更高的亲和力。经细胞色素a-597的途径在能量保存方面比经细胞色素b-561的途径更有效，后者缺乏氧化磷酸化的位点III。
