ATP5PF
# ATP5PF

ATP synthase-coupling factor 6, mitochondrial is an enzyme subunit that in humans is encoded by the ATP5PF gene.

## Function

Mitochondrial ATP synthase catalyzes ATP synthesis, utilizing an electrochemical gradient of protons across the inner membrane during oxidative phosphorylation. It is composed of two linked multi-subunit complexes: the soluble catalytic core, $F_1,$ and the membrane-spanning component, $F_O,$ which comprises the proton channel. The $F_1$ complex consists of 5 different subunits (alpha, beta, gamma, delta, and epsilon) assembled in a ratio of 3 alpha, 3 beta, and a single representative of the other 3. The $F_O$ seems to have nine subunits (a, b, c, d, e, f, g, F6 and 8). This gene encodes the F6 subunit of the $F_O$ complex, required for $F_1$ and $F_O$ interactions. Alternatively spliced transcript variants encoding different isoforms have been identified for this gene.

The F6 subunit is part of the peripheral stalk that links the $F_1$ and $F_O$ complexes together, and which acts as a stator to prevent certain subunits from rotating with the central rotary element. The peripheral stalk differs in subunit composition between mitochondrial, chloroplast and bacterial F-ATPases. In mitochondria, the peripheral stalk is composed of one copy each of subunits OSCP (oligomycin sensitivity conferral protein), F6, b and d. There is no homologue of subunit F6 in bacterial or chloroplast F-ATPase, whose peripheral stalks are composed of one copy of the delta subunit (homologous to OSCP), and two copies of subunit b in bacteria, or one copy each of subunits b and b' in chloroplasts and photosynthetic bacteria.

