1kyo

YEAST CYTOCHROME BC1 COMPLEX WITH BOUND SUBSTRATE CYTOCHROME CYEAST CYTOCHROME BC1 COMPLEX WITH BOUND SUBSTRATE CYTOCHROME C

Structural highlights

1kyo is a 20 chain structure with sequence from Mus musculus and Saccharomyces cerevisiae. The December 2002 RCSB PDB Molecule of the Month feature on Cytochrome c by David S. Goodsell is 10.2210/rcsb_pdb/mom_2002_12. The May 2011 RCSB PDB Molecule of the Month feature on Cytochrome bc1 by David Goodsell is 10.2210/rcsb_pdb/mom_2011_5. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.97Å
Ligands:	, , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

QCR1_YEAST Component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is part of the mitochondrial respiratory chain that generates an electrochemical potential coupled to ATP synthesis. The complex couples electron transfer from ubiquinol to cytochrome c. COR1 may mediate formation of the complex between cytochromes c and c1.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Small diffusible redox proteins facilitate electron transfer in respiration and photosynthesis by alternately binding to integral membrane proteins. Specific and transient complexes need to be formed between the redox partners to ensure fast turnover. In respiration, the mobile electron carrier cytochrome c shuttles electrons from the cytochrome bc1 complex to cytochrome c oxidase. Despite extensive studies of this fundamental step of energy metabolism, the structures of the respective electron transfer complexes were not known. Here we present the crystal structure of the complex between cytochrome c and the cytochrome bc1 complex from Saccharomyces cerevisiae. The complex was crystallized with the help of an antibody fragment, and its structure was determined at 2.97-A resolution. Cytochrome c is bound to subunit cytochrome c1 of the enzyme. The tight and specific interactions critical for electron transfer are mediated mainly by nonpolar forces. The close spatial arrangement of the c-type hemes unexpectedly suggests a direct and rapid heme-to-heme electron transfer at a calculated rate of up to 8.3 x 10(6) s(-1). Remarkably, cytochrome c binds to only one recognition site of the homodimeric multisubunit complex. Interestingly, the occupancy of quinone in the Qi site is higher in the monomer with bound cytochrome c, suggesting a coordinated binding and reduction of both electron-accepting substrates. Obviously, cytochrome c reduction by the cytochrome bc1 complex can be regulated in response to respiratory conditions.

Crystal structure of the yeast cytochrome bc1 complex with its bound substrate cytochrome c.,Lange C, Hunte C Proc Natl Acad Sci U S A. 2002 Mar 5;99(5):2800-5. PMID:11880631^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Lange C, Hunte C. Crystal structure of the yeast cytochrome bc1 complex with its bound substrate cytochrome c. Proc Natl Acad Sci U S A. 2002 Mar 5;99(5):2800-5. PMID:11880631 doi:10.1073/pnas.052704699

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OCA

[1] Lange C, Hunte C. Crystal structure of the yeast cytochrome bc1 complex with its bound substrate cytochrome c. Proc Natl Acad Sci U S A. 2002 Mar 5;99(5):2800-5. PMID:11880631 doi:10.1073/pnas.052704699

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