Cytochrome bc1 complex: Difference between revisions

Latest revision as of 13:45, 12 February 2023

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.^[1]

More details in Complex III of Electron Transport Chain.

Structural highlights

Cbc1 is a composed of 11 proteins and cofactors which include heme-carrying proteins like and and iron-sulfur cluster proteins like . The iron containing moieties are , (where vinyl side chain of heme are replaced by thioether) and . ^[2]

Cytochrome bc1 containing Cb (green), Cc1 (yellow), RISP (beige) and Fe2S2 complex with stigmatellin (PDB entry 1zrt)

Drag the structure with the mouse to rotate

3D structures of cytochrome bc13D structures of cytochrome bc1

Cytochrome bc1 3D structures

ReferencesReferences

↑ Crofts AR. The cytochrome bc1 complex: function in the context of structure. Annu Rev Physiol. 2004;66:689-733. PMID:14977419 doi:http://dx.doi.org/10.1146/annurev.physiol.66.032102.150251
↑ Berry EA, Huang LS, Saechao LK, Pon NG, Valkova-Valchanova M, Daldal F. X-Ray Structure of Rhodobacter Capsulatus Cytochrome bc (1): Comparison with its Mitochondrial and Chloroplast Counterparts. Photosynth Res. 2004;81(3):251-75. PMID:16034531 doi:http://dx.doi.org/10.1023/B:PRES.0000036888.18223.0e

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Michal Harel, Alexander Berchansky, Karl Oberholser, Jaime Prilusky, Joel L. Sussman

[1] Crofts AR. The cytochrome bc1 complex: function in the context of structure. Annu Rev Physiol. 2004;66:689-733. PMID:14977419 doi:http://dx.doi.org/10.1146/annurev.physiol.66.032102.150251

[2] Berry EA, Huang LS, Saechao LK, Pon NG, Valkova-Valchanova M, Daldal F. X-Ray Structure of Rhodobacter Capsulatus Cytochrome bc (1): Comparison with its Mitochondrial and Chloroplast Counterparts. Photosynth Res. 2004;81(3):251-75. PMID:16034531 doi:http://dx.doi.org/10.1023/B:PRES.0000036888.18223.0e

[1]

[2]

@@ Line 3: / Line 3: @@
 '''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]].
+More details in [[Complex III of Electron Transport Chain]].
 == Structural highlights ==
@@ Line 10: / Line 10: @@
 </StructureSection>
 ==3D structures of cytochrome bc1==
+[[Cytochrome bc1 3D structures]]
-Updated on {{REVISIONDAY2}}-{{MONTHNAME|{{REVISIONMONTH}}}}-{{REVISIONYEAR}}
-[[1bgy]], [[1be3]], [[1l0n]], [[1ntm]] - bCb + bCc1 + RISP – bovine <BR />
-[[1qcr]] - bCb + bCc1 + RISP – Cα model<BR />
-[[1sqp]], [[2fyu]], [[1l0l]], [[1ntk]], [[1pp9]], [[1ppj]], [[1sqb]], [[2a06]], [[1sqv]], [[1sqx]], [[1sqq]] - bCb + bCc1 + RISP + inhibitor<BR />
-[[4d6u]] - bCb + bCc1 + RISP + antimalarial pyridone<BR />
-[[1ntz]] - bCb + bCc1 + RISP + ubiquinone<BR />
-[[1nu1]] - bCb + bCc1 + RISP + quinolone derivative<BR />
-[[2yiu]] - Cb + Cc1 + RISP – ''Paracoccus denitrificans''<BR />
-[[3cxh]], [[3h1h]], [[1bcc]], [[3h1h]] - cCb + cCc1 + RISP - chicken<BR />
-[[3cwb]], [[3h1i]], [[3h1j]], [[3h1k]], [[3h1l]], [[3l70]], [[3l71]], [[3l72]], [[3l73]], [[3l74]], [[3l75]], [[3tgu]], [[3bcc]], [[2bcc]], [[3h1i]] - cCb + cCc1 + RISP + inhibitor<BR />
-[[2qjk]] - RsCb (mutant) + RsCc1 + RISP + inhibitor<BR />
-[[2qjp]] - RsCb + RsCc1 + RISP + inhibitor<BR />
-[[2qjy]] - RsCb (mutant) + RsCc1 + RISP (mutant) + inhibitor<BR />
-[[2ibz]], [[1kyo]], [[1kb9]], [[1p84]] - yCb + yCc1 + RISP + inhibitor - yeast<BR />
-[[3cx5]] - yCb + yCc1 + RISP <BR />
-[[1ezv]] - yCb + yCc1 + RISP + antibody<BR />
-[[6t0b]], [[6t15]] - yCb in mitochondrial III-IV complex - Cryo EM <BR />
-[[2yiu]] - Cb + Cc1 + RISP – ''Paracoccus denitrificans''<BR />
-[[2fyn]] - RsCb (mutant) + Cc1 + RISP – ''Rhodobacter sphaeroides''<BR />
-[[1zrt]] - Cb + Cc1 + RISP – ''Rhodobacter capsulatus''<BR />
 == References ==