ISSN:
1432-1327
Keywords:
Key words Dimeric cytochrome c3
;
Ab initio structure
;
Disulfide bridges
;
Thiosulfate reduction
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract The 1.2 Å resolution crystal structure of the 29 kDa di-tetrahaem cytochrome c 3 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 c 3 from Desulfomicrobium norvegicum. Each monomer has the typical polypeptide fold, haem arrangement and iron coordination found for the tetrahaem cytochrome c 3 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s007750050299
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