Purification and biochemical characterization of a putative [6Fe-6S] prismane-cluster-containing protein from Desulfovibrio vulgaris (Hildenborough).
A novel iron-sulfur protein has been isolated from the sulfate-reducing bacterium Desulfovibrio vulgaris (Hildenborough). It is a stable monomeric protein, which has a molecular mass of 52 kDa, as determined by sedimentation-equilibrium centrifugation. Analysis of the metal and acid-labile sulfur content of the protein revealed the presence of 6.3 +/- 0.4 Fe/polypeptide and 6.2 +/- 0.7 S2-/polypeptide. Non-iron transition metals, heme, flavin and selenium were absent. Combining these data with the observation of a very anisotropic S = 1/2 [6Fe-6S]3+ prismane-like EPR signal in the dithionite-reduced protein, we believe that we have encountered the first example of a prismane-cluster-containing protein. The prismane protein has a slightly acidic amino acid composition and isoelectric point (pI = 4.9). The ultraviolet/visible spectrum is relatively featureless (epsilon 280 = 81 mM-1.cm-1, epsilon 400 = 25 mM-1.cm-1, epsilon 400,red = 14 mM-1.cm-1). The shape of the protein is approximately globular (S20.w = 4.18 S). The N-terminal amino acid sequence is MFS/CFQS/C QETAKNTG. Polyclonal antibodies against the protein were raised. Cytoplasmic localization was inferred from subcellular fractionation studies. Cross-reactivity of antibodies against this protein indicated the occurrence of a similar protein in D. vulgaris (Monticello) and Desulfovibrio desulfuricans (ATCC 27774). We have not yet identified a physiological function for the prismane protein despite trials for some relevant enzyme activities.
Pierik
A J
AJ
Department of Biochemistry, Agricultural University, Wageningen, The Netherlands.
Wolbert
R B
RB
Mutsaers
P H
PH
Hagen
W R
WR
Veeger
C
C
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001426:Bacterial Proteins / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D003593:Cytoplasm / Q000737:chemistry; D016969:Desulfovibrio vulgaris / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D007501:Iron / Q000032:analysis; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000502:physiology; D008670:Metals / Q000032:analysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013045:Species Specificity; D013053:Spectrophotometry; D013455:Sulfur / Q000032:analysis
D000596:Amino Acids; D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; D008670:Metals; C075199:prismane protein, Desulfovibrio vulgaris; D013455:Sulfur; D007501:Iron