3H1H

Cytochrome bc1 complex from chicken

Summary for 3H1H

• Entry DOI: 10.2210/pdb3h1h/pdb
• Related: 1bcc 2fyu 2ppj 3H1I 3H1J 3H1K 3H1L 3cx5
• Descriptor: UBIQUINOL-CYTOCHROME-C REDUCTASE COMPLEX CORE PROTEIN I, MITOCHONDRIAL, UBIQUINOL-CYTOCHROME C REDUCTASE COMPLEX 7.2 KDA PROTEIN, UNKNOWN LIGAND, ... (20 entities in total)
• Functional Keywords: cytochrome bc1, membrane protein, heme protein, rieske iron sulfur protein, cytochrome b, cytochrome c1, complex iii, mitochondrial processing protease, ubiquinone, oxidoreductase, redox enzyme, respiratory chain, electron transport, heme, iron, membrane, metal-binding, mitochondrion, mitochondrion inner membrane, transmembrane, transport, disulfide bond, iron-sulfur, transit peptide
• Biological source: Gallus gallus (chicken); More
• Total number of polymer chains: 20
• Total formula weight: 479842.77

Authors

Zhang, Z.,Huang, L.,Shulmeister, V.M.,Chi, Y.I.,Kim, K.K.,Hung, L.W.,Crofts, A.R.,Berry, E.A.,Kim, S.H. (deposition date: 2009-04-12, release date: 2009-04-28, Last modification date: 2020-07-29)

Primary citation

Zhang, Z.,Huang, L.,Shulmeister, V.M.,Chi, Y.I.,Kim, K.K.,Hung, L.W.,Crofts, A.R.,Berry, E.A.,Kim, S.H.
Electron Transfer by Domain Movement in Cytochrome Bc1
Nature, 392:677-684, 1998

PubMed Abstract: The cytochrome bc1 is one of the three major respiratory enzyme complexes residing in the inner mitochondrial membrane. Cytochrome bc1 transfers electrons from ubiquinol to cytochrome c and uses the energy thus released to form an electrochemical gradient across the inner membrane. Our X-ray crystal structures of the complex from chicken, cow and rabbit in both the presence and absence of inhibitors of quinone oxidation, reveal two different locations for the extrinsic domain of one component of the enzyme, an iron-sulphur protein. One location is close enough to the supposed quinol oxidation site to allow reduction of the Fe-S protein by ubiquinol. The other site is close enough to cytochrome c1 to allow oxidation of the Fe-S protein by the cytochrome. As neither location will allow both reactions to proceed at a suitable rate, the reaction mechanism must involve movement of the extrinsic domain of the Fe-S component in order to shuttle electrons from ubiquinol to cytochrome c1. Such a mechanism has not previously been observed in redox protein complexes.

PubMed: 9565029

Experimental method

X-RAY DIFFRACTION (3.16 Å)