Purification and characterization of desulfoferrodoxin. A novel protein from Desulfovibrio desulfuricans (ATCC 27774) and from Desulfovibrio vulgaris (strain Hildenborough) that contains a distorted rubredoxin center and a mononuclear ferrous center.
A new type of non-heme iron protein was purified to homogeneity from extracts of Desulfovibrio desulfuricans (ATCC 27774) and Desulfovibrio vulgaris (strain Hildenborough). This protein is a monomer of 16-kDa containing two iron atoms per molecule. The visible spectrum has maxima at 495, 368, and 279 nm and the EPR spectrum of the native form shows resonances at g = 7.7, 5.7, 4.1 and 1.8 characteristic of a high-spin ferric ion (S = 5/2) with E/D = 0.08. Mössbauer data indicates the presence of two types of iron: an FeS4 site very similar to that found in desulforedoxin from Desulfovibrio gigas and an octahedral coordinated high-spin ferrous site most probably with nitrogen/oxygen-containing ligands. Due to this rather unusual combination of active centers, this novel protein is named desulfoferrodoxin. Based on NH2-terminal amino acid sequence determined so far, the desulfoferrodoxin isolated from D. desulfuricans (ATCC 27774) appears to be a close analogue to a recently discovered gene product from D. vulgaris (Brumlik, M.J., and Voordouw, G. (1989) J. Bacteriol. 171, 49996-50004), which was suggested to be a rubredoxin oxidoreductase. However, reduced pyridine nucleotides failed to reduce the desulforedoxin-like center of this new protein.
Moura
I
I
Centro de Tecnologia Química e Biológica, Oeiras, Portugal.
Tavares
P
P
Moura
J J
JJ
Ravi
N
N
Huynh
B H
BH
Liu
M Y
MY
LeGall
J
J
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D003901:Desulfovibrio / Q000032:analysis*; D004578:Electron Spin Resonance Spectroscopy; D005288:Ferredoxins / Q000737:chemistry / Q000302:isolation & purification*; D007501:Iron / Q000032:analysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000737:chemistry; D013057:Spectrum Analysis
D000596:Amino Acids; D005288:Ferredoxins; D010446:Peptide Fragments; C066602:desulfoferrodoxin; D007501:Iron