Editing ATP synthase (section)

=== F<sub>O</sub> region ===
[[File:Fo complex subunit F6.png|thumb|285x285px|F<sub>O</sub> subunit F6 from the peripheral stalk region of ATP synthase.<ref name="Carbajo_2004">{{PDB|1VZS}}; {{cite journal | vauthors = Carbajo RJ, Silvester JA, Runswick MJ, Walker JE, Neuhaus D | title = Solution structure of subunit F(6) from the peripheral stalk region of ATP synthase from bovine heart mitochondria | journal = Journal of Molecular Biology | volume = 342 | issue = 2 | pages = 593–603 | date = September 2004 | pmid = 15327958 | doi = 10.1016/j.jmb.2004.07.013 }}</ref>]]

F<sub>O</sub> is a water [[insoluble]] protein with eight subunits and a transmembrane ring. The ring has a [[tetramer]]ic shape with a [[helix-loop-helix]] protein that goes through conformational changes when protonated and deprotonated, pushing neighboring subunits to rotate, causing the spinning of F<sub>O</sub> which then also affects conformation of F<sub>1</sub>, resulting in switching of states of alpha and beta subunits. The F<sub>O</sub> region of ATP synthase is a proton pore that is embedded in the mitochondrial membrane. It consists of three main subunits, a, b, and c. Six c subunits make up the rotor ring, and subunit b makes up a stalk connecting to F<sub>1</sub> OSCP that prevents the αβ hexamer from rotating. Subunit a connects b to the c ring.<ref name=ecoli/> Humans have six additional subunits, [[ATP5H|d]], [[ATP5I|e]], [[ATP5J2|f]], [[ATP5L|g]], [[ATP5J|F6]], and [[MT-ATP8|8]] (or A6L). This part of the enzyme is located in the mitochondrial inner membrane and couples proton translocation to the rotation that causes ATP synthesis in the F<sub>1</sub> region.

In eukaryotes, mitochondrial F<sub>O</sub> forms membrane-bending dimers. These dimers self-arrange into long rows at the end of the [[cristae]], possibly the first step of cristae formation.<ref>{{cite journal | vauthors = Blum TB, Hahn A, Meier T, Davies KM, Kühlbrandt W | title = Dimers of mitochondrial ATP synthase induce membrane curvature and self-assemble into rows | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 116 | issue = 10 | pages = 4250–4255 | date = March 2019 | pmid = 30760595 | pmc = 6410833 | doi = 10.1073/pnas.1816556116 | bibcode = 2019PNAS..116.4250B | doi-access = free }}</ref> An atomic model for the dimeric yeast F<sub>O</sub> region was determined by cryo-EM at an overall resolution of 3.6 Å.<ref>{{cite journal | vauthors = Guo H, Bueler SA, Rubinstein JL | title = Atomic model for the dimeric F<sub>O</sub> region of mitochondrial ATP synthase | journal = Science | volume = 358 | issue = 6365 | pages = 936–940 | date = November 2017 | pmid = 29074581 | pmc = 6402782 | doi = 10.1126/science.aao4815 | bibcode = 2017Sci...358..936G }}</ref>
{| class="wikitable" style="text-align:center"
|+ F<sub>O</sub>-Main subunits
|-
! Subunit !! Human Gene
|-
| a || ''[[MT-ATP6]]''
|-
| b || ''[[ATP5PB]]''
|-
| [[ATP synthase subunit C|c]] || ''[[ATP5MC1]]'', ''[[ATP5G2]]'', ''[[ATP5G3]]''
|-
|}