• Prosthetic group features
• Adrenodoxin­type ferredoxins in motif databases
• Adrenodoxin­type ferredoxins in alignment databases
• Adrenodoxin­type ferredoxins in 3­D databases
• References

Iron-sulphur cluster	Formal oxidation/spin states
[Fe2S2](SCys)4	[Fe2S2]+ (S=1/2); [Fe2S2]2+ (S=0)

Adrenodoxin, putidaredoxin and terpredoxin are soluble Fe₂S₂ iron-sulphur proteins that act as single electron carriers. In mitochondrial monooxygenase systems, adrenodoxin transfers an electron from NADPH:adrenodoxin reductase to membrane­bound P450 [1, 2]. In bacteria, putidaredoxin and terpredoxin serve as electron carriers between corresponding NADH­dependent ferredoxin reductases and soluble P450 [3, 4]. The exact functions of other members of this family are not known.

The 3­D structures of putidaredoxin [5] and adrenodoxin [6] have been solved. Despite low sequence similarity between adrenodoxin­type and plant­type ferredoxins, putidaredoxin and adrenodoxin retain a similar folding topology to structurally characterised plant­type ferredoxins. The fold belongs to the +ß class, with 3-5 ­helices and 5-6 ß­strands forming a barrel­like structure, and an extruded loop containing three of the four cysteinyl residues of the iron-sulphur cluster:

                       I     II III 
                     ,-C-----C--C---.
                     |  \   /  /     \
                     |   [Fe2S2]      |
                  +H3N      \         |
                         ,--C---.    /
                         |  IV  `---'
                  ¯OOC---'     

Adrenodoxin­type ferredoxins in motif databases

PRINTS ID	PRINTS AC	PROSITE/BLOCKS ID	PROSITE AC	BLOCKS AC
ADRENODOXIN	PR00355	ADX	PS00814	BL00814

Adrenodoxin­type ferredoxins in alignment databases

Protein Superfamily	Protein Homology Domain	Pfam	LPFC 3­D alignment
00029; ferredoxin [2Fe-2S]	00254; ferredoxin [2Fe-2S]	PF00111; fer2	-

Adrenodoxin­type ferredoxins in 3­D databases

PDB	scop	BSM	RELI Base	Header	¹
1ayf	-	1ayf	-	Adrenodoxin (oxidised) (complex with glycerol); bovine (recombinant form expressed in Escherichia coli)	-
1put	1put	1put	1put	Putidaredoxin (oxidised); Pseudomonas putida, strain ATCC 17453)	MS5GA4

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

References

1. Hanukoglu, I. (1992) Steroidogenic enzymes: structure, function, and regulation of expression. J. Steroid Biochem. Mol. Biol. 43, 779-804.
2. Coghlan, V.M. and Vickery, L.E. (1992) Electrostatic interactions stabilizing ferredoxin electron transfer complexes. Disruption by "conservative" mutations. J. Biol. Chem. 267, 8932-8935.
3. Peterson, J.A., Lorence, M.C. and Amarneh, B. (1990) Putidaredoxin reductase and putidaredoxin. Cloning, sequence determination, and heterologous expression of the proteins. J. Biol. Chem. 265, 6066-6073.
4. Peterson, J.A., Lu, J.Y., Geisselsoder, J., Graham­Lorence, S., Carmona, C., Witney, F. and Lorence, M.C. (1992) Cytochrome P­450terp. Isolation and purification of the protein and cloning and sequencing of its operon. J. Biol. Chem. 267, 14193-14203.
5. Pochapsky, T.C., Ye, X.M., Ratnaswamy, G. and Lyons, T.A. (1994) An NMR­derived model for the solution structure of oxidized putidaredoxin, a 2­Fe, 2­S ferredoxin from Pseudomonas. Biochemistry 33, 6424-6432.
6. Müller, A., Müller, J.J., Müller, Y.A., Uhlmann, H., Bernhardt, R. and Heinemann, U. (1998) New aspects of electron transfer revealed by the crystal structure of a truncated bovine adrenodoxin, Adx(4-108). Structure 6, 269-280.

Bibliography on structural studies of adrenodoxin­type ferredoxins