Cytochrome b6f complex: Difference between revisions

The '''cytochrome ''b'''''₆'''''f'' complex''' ([[plastoquinol—plastocyanin reductase]] or plastoquinol/plastocyanin oxidoreductase; {{EC number|7.1.1.6}}) is an enzyme found in the [[thylakoid]] membrane in [[chloroplast]]s of plants, [[cyanobacteria]], and [[green algae]], that catalyzes the transfer of electrons from [[plastoquinol]] to [[plastocyanin]]:
: [[plastoquinol]] + 2 oxidized [[plastocyanin]] [side 1] <math>\rightleftharpoons</math> [[plastoquinone]] + 2 reduced [[plastocyanin]] + 2 H⁺ [side 2].<ref name=Berg>{{cite book | last1 = Berg | first1 = Jeremy M. | last2 = Tymoczko | first2 = John L. | last3 = Stryer | first3 = Lubert | last4 = Stryer | first4 = Lubert | name-list-style = vanc | title = Biochemistry | url = https://archive.org/details/biochemistry0006berg | url-access = registration | year = 2007 | publisher = W.H. Freeman | location = New York | isbn = 978-0-7167-8724-2 }}</ref>
The reaction is analogous to the reaction catalyzed by [[cytochrome bc1 complex|cytochrome bc₁]] (Complex III) of the [[mitochondria]]l [[electron transport chain]]. During [[photosynthesis]], the cytochrome b₆f complex is one step along the chain that transfers [[electrons]] from [[Photosystem II]] to [[Photosystem I]], and at the same time pumps protons into the thylakoid space, contributing to the generation of an electrochemical (energy) gradient<ref name="Hasan-2013a">{{cite journal | vauthors = Hasan SS, Yamashita E, Baniulis D, Cramer WA | title = Quinone-dependent proton transfer pathways in the photosynthetic cytochrome b6f complex | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 110 | issue = 11 | pages = 4297–302 | date = Mar 2013 | pmid = 23440205 | pmc = 3600468 | doi = 10.1073/pnas.1222248110 | doi-access = free }}</ref> that is later used to synthesize [[adenosine triphosphate|ATP]] from [[adenosine diphosphate|ADP]].