• Prosthetic group features
• Rubredoxins in motif databases
• Rubredoxins in alignment databases
• Rubredoxins in 3­D databases
• References

Iron-sulphur cluster	Formal oxidation states
Fe(SCys)4	[Fe(Cys)4]1-; [Fe(Cys)4]2-

Rubredoxin is a low molecular weight iron­containing bacterial protein involved in electron transfer, sometimes replacing ferredoxin as an electron carrier [1]. Rubrerythrin is a fusion protein containing a C­terminal domain homologous to rubredoxin [2].

The 3­D structures of a number of rubredoxins have been solved [3, 4]. The fold belongs to the +ß class, with 2 ­helices and 2-3 ß­strands. Its active site contains an iron ion which is co­ordinated by the sulphurs of four conserved cysteine residues forming an almost regular tetrahedron [4]. The conserved cysteines reside on two loops, which are the most conserved regions of the protein:

                 +H3N---.
                        |        ,---.
                        |  I  II |   |
                        `--C--C--'   |
                           \  /      |
                           [Fe]      |
                           /  \      |
                        ,--C--C--.   |
                        | IV III |   |
                        |        `---'
                 ¯OOC---'

Rubredoxin­type Fe(Cys)₄ proteins in motif databases

PRINTS ID	PRINTS AC	PROSITE/BLOCKS ID	PROSITE AC	BLOCKS AC
RUBREDOXIN	PR00163	RUBREDOXIN	PS00202	BL00202

Rubredoxin­type Fe(Cys)₄ proteins in alignment databases

Protein Superfamily	Protein Homology Domain	Pfam	LPFC 3­D alignment
00033; rubredoxin 00034; Pseudomonas rubredoxin I 00035; Pseudomonas rubredoxin II	00142; rubredoxin	PF00301; rubredoxin	rub

Rubredoxin­type Fe(Cys)₄ proteins in 3­D databases

PDB	scop	BSM	RELI Base	Header	¹
1be7	-	1be7	1be7	Rubredoxin (oxidised) (C42S mutant); Clostridium pasteurianum	-
1bq8	-	1bq8	1bq8	Rubredoxin (N­terminal methionine mutant); Pyrococcus furiosus	-
1bq9	-	1bq9	1bq9	Rubredoxin (N­terminal formylmethionine mutant); Pyrococcus furiosus	-
1brf	-	1brf	1brf	Rubredoxin (wild type); Pyrococcus furiosus	-
1caa	1caa	1caa	1caa	Rubredoxin (oxidised); Pyrococcus furiosus	MMS93186
1cad	1cad	1cad	1cad	Rubredoxin (reduced); Pyrococcus furiosus	MMS93186
1irn	1irn	1irn	1irn	Rubredoxin (oxidised); Clostridium pasteurianum	-
1iro	1iro	1iro	1iro	Rubredoxin (oxidised); Clostridium pasteurianum	-
1rdg	1rdg	1rdg	1rdg	Rubredoxin; Desulfovibrio gigas	-
1zrp*	1zrp*	1zrp*	1zrp*	Rubredoxin (Zn­substituted); Pyrococcus furiosus	MMS93185*
4rxn	4rxn	4rxn	4rxn	Rubredoxin (oxidised) (unconstrained model); Clostridium pasteurianum	-
5rxn	5rxn	5rxn	5rxn	Rubredoxin (oxidised) (constrained model); Clostridium pasteurianum	-
6rxn	6rxn	6rxn	6rxn	Rubredoxin; Desulfovibrio desulfuricans, strain 27774	MMS91112
7rxn	7rxn	7rxn	7rxn	Rubredoxin (complex with sulphate); Desulfovibrio vulgaris	-
8rxn	8rxn	8rxn	8rxn	Rubredoxin (complex with sulphate); Desulfovibrio vulgaris	-
-	-	-	-	Rubredoxin (racemic); Desulfovibrio desulfuricans	MMS94233

¹ Macromolecular Structures abstract. Full text is available to BioMedNet Members

References

1. Lee, W.Y., Brune, D.C., LoBrutto, R. and Blankenship, R.E. (1995) Isolation, characterization, and primary structure of rubredoxin from the photosynthetic bacterium, Heliobacillus mobilis. Arch. Biochem. Biophys. 318, 80-88.
2. van Beeumen, J.J., van Driessche, G., Liu, M.Y. and LeGall, J. (1991) The primary structure of rubrerythrin, a protein with inorganic pyrophosphatase activity from Desulfovibrio vulgaris. Comparison with hemerythrin and rubredoxin. J. Biol. Chem. 266, 20645-20653.
3. Day, M.W., Hsu, B.T., Joshua­Tor, L., Park, J.B., Zhou, Z.­H., Adams, M.W.W. and Rees, D.C. (1992) X­ray crystal structures of the oxidized and reduced forms of the rubredoxin from the marine hyperthermophilic archaebacterium Pyrococcus furiosus. Protein Science 1, 1494-1507.
4. Frey, M., Sieker, L., Payan, F., Haser, R., Bruschi, M., Pepe, G. and LeGall, J. (1987) Rubredoxin from Desulfovibrio gigas. A molecular model of the oxidized form at 1.4 Å resolution. J. Mol. Biol. 197, 525-441.

Bibliography on structural studies of rubredoxins

Bibliography on structural studies of rubrerythrin