Electron and proton transfer in the M. smegmatis IIIIV supercomplex.

The M. smegmatis respiratory IIIIV supercomplex consists of a complex III (CIII) dimer flanked on each side by a complex IV (CIV) monomer, electronically connected by a di-heme cyt. cc subunit of CIII.

Identification of a cytochrome bc-aa supercomplex in Rhodobacter sphaeroides.

Respiration is carried out by a series of membrane-bound complexes in the inner mitochondrial membrane or in the cytoplasmic membrane of bacteria. Increasing evidence shows that these complexes organize into larger supercomplexes. In this work, we identified a supercomplex composed of cytochrome (cyt.

Membrane-tethering of cytochrome c accelerates regulated cell death in yeast.

Intrinsic apoptosis as a modality of regulated cell death is intimately linked to permeabilization of the outer mitochondrial membrane and subsequent release of the protein cytochrome c into the cytosol, where it can participate in caspase activation via apoptosome formation. Interestingly, cytochrome c release is an ancient feature of regulated cell death even in unicellular eukaryotes that do not contain an apoptosome. Therefore, it was speculated that cytochrome c release might have an additional, more fundamental role for cell death signalling, because its absence from mitochondria disrupts oxidative phosphorylation.

Structure of a functional obligate complex IIIIV respiratory supercomplex from Mycobacterium smegmatis.

In the mycobacterial electron-transport chain, respiratory complex III passes electrons from menaquinol to complex IV, which in turn reduces oxygen, the terminal acceptor. Electron transfer is coupled to transmembrane proton translocation, thus establishing the electrochemical proton gradient that drives ATP synthesis. We isolated, biochemically characterized, and determined the structure of the obligate IIIIV supercomplex from Mycobacterium smegmatis, a model for Mycobacterium tuberculosis.

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

Complex III in C. glutamicum has an unusual di-heme cyt. c and it co-purifies with complex IV in a supercomplex.