Rapid Electron Transfer within the III-IV Supercomplex in Corynebacterium glutamicum.

ABSTRACT: Complex III in C. glutamicum has an unusual di-heme cyt. c₁ and it co-purifies with complex IV in a supercomplex. Here, we investigated the kinetics of electron transfer within this supercomplex and in the cyt. aa₃ alone (cyt. bc₁ was removed genetically). In the reaction of the reduced cyt. aa₃ with O₂, we identified the same sequence of events as with other A-type oxidases. However, even though this reaction is associated with proton uptake, no pH dependence was observed in the kinetics. For the cyt. bc₁-cyt. aa₃ supercomplex, we observed that electrons from the c-hemes were transferred to Cu_A with time constants 0.1-1 ms. The b-hemes were oxidized with a time constant of 6.5 ms, indicating that this

SUBMITTER: Graf S 

PROVIDER: S-EPMC5040959 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature