JBIC Journal of Biological Inorganic Chemistry

, Volume 4, Issue 2, pp 162–165

Ab initio structure solution of a dimeric cytochrome c3 from Desulfovibrio gigas containing disulfide bridges

  • Carlos Frazão
  • Larry Sieker
  • George Sheldrick
  • Victor Lamzin
  • Jean LeGall
  • M. A. Carrondo
ORIGINAL ARTICLE

DOI: 10.1007/s007750050299

Cite this article as:
Frazão, C., Sieker, L., Sheldrick, G. et al. JBIC (1999) 4: 162. doi:10.1007/s007750050299

Abstract

 The 1.2 Å resolution crystal structure of the 29 kDa di-tetrahaem cytochrome c3 from the sulfate reducing bacterium Desulfovibrio gigas was solved by ab initio methods, making this the largest molecule to be solved by this procedure. The actual refined model of the cysteine-linked dimeric molecule reveals that this molecule is very similar to the non-covalently linked symmetrical dimer of the di-tetrahaem cytochrome c3 from Desulfomicrobium norvegicum. Each monomer has the typical polypeptide fold, haem arrangement and iron coordination found for the tetrahaem cytochrome c3 molecules. The interface between the covalently linked monomers in the asymmetric unit of the crystal shows a pseudo two-fold arrangement, disturbed from symmetry by crystal packing forces. The fact that D. gigas contains a dimeric tetrahaem cytochrome with solvent accessible disulfide bridges and that this cytochrome specifically couples hydrogen oxidation to thiosulfate reduction in bacterial extracts provides an interesting aspect related to disulfide exchange reactions in this microorganism.

Key words Dimeric cytochrome c3Ab initio structureDisulfide bridgesThiosulfate reduction

Copyright information

© Society of Biological Inorganic Chemistry 1999

Authors and Affiliations

  • Carlos Frazão
    • 5
  • Larry Sieker
    • 1
  • George Sheldrick
    • 2
  • Victor Lamzin
    • 3
  • Jean LeGall
    • 4
  • M. A. Carrondo
    • 5
  1. 1.Department of Biological Structure, University of Washington Seattle, WA 98195, USAUS
  2. 2.Institut für Anorganische Chemie der Universität Göttingen Tammannstrasse 4, D-37077 Göttingen, GermanyDE
  3. 3.European Molecular Biology Laboratory, c/o DESY Notkestrasse 85, D-22603 Hamburg, GermanyDE
  4. 4.Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USAGE
  5. 5.Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apart. 127, P-2780 Oeiras, Portugal e-mail: corrondo@itqb.un1.pt Tel.: +351-1-4469657 Fax: +351-1-4433644PT