View source for Cytochrome bc1 complex

<StructureSection load='' size='350' side='right' caption='Cytochrome bc1 containing Cb (green), Cc1 (yellow), RISP (beige) and Fe2S2 complex with stigmatellin (PDB entry [[1zrt]])' scene='49/490879/Cv/6'>

'''Cytochrome bc1''' (Cbc1) functions as the central pump which transfers protons across the cell membrane.  The protons are used to power the rotation of ATP synthase.  Cbc1 binds ubiquinol which carries hydrogen atoms.  Cbc1 separates the protons and the electrons.  The protons are released in the inner side of the membrane for use by ATP synthase and the electrons are transferred to cytochrome c or to the outer side of the membrane.  Plants use '''cytochrome b6f''' in the same manner binding plastoquinol as a hydrogen carrier.  Stigmatellin inhibits the Cbc1 electron transfer by binding to its quinone oxidation site.  Antimycin inhibits Cbc1 by binding to its quinone reduction site.<ref>PMID:14977419</ref>

More details in [[Complex III of Electron Transport Chain]].  

== Structural highlights ==

Cbc1 is a <scene name='49/490879/Cv/11'>dimeric protein</scene> composed of 11 proteins and cofactors which include heme-carrying proteins like <scene name='49/490879/Cv/12'>cytochrome b (Cb)</scene> and <scene name='49/490879/Cv/13'>cytochrome c1 (Cc1)</scene> and iron-sulfur cluster proteins like <scene name='49/490879/Cv/14'>Rieske Fe-S protein (RISP)</scene>.  The iron containing moieties are <scene name='49/490879/Cv/15'>heme</scene>, <scene name='49/490879/Cv/16'>heme C</scene> (where vinyl side chain of heme are replaced by thioether) and <scene name='49/490879/Cv/17'>Fe2S2</scene>. <ref>PMID:16034531</ref>
</StructureSection>
==3D structures of cytochrome bc1==
[[Cytochrome bc1 3D structures]]

== References ==
<references/>



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