|PROSITE documentation PDOC00175|
Ferredoxins are small, acidic, electron transfer proteins that are ubiquitous in biological redox systems. They have either 4Fe-4S, 3Fe-4S, or 2Fe-2S cluster. Among them, ferredoxin with one 2Fe-2S cluster per molecule are present in plants, animals, and bacteria, and form a distinct 2Fe-Ferredoxin family [1,2]. They are proteins of around one hundred amino acids with four conserved cysteine residues to which the 2Fe-2S cluster is ligated. This conserved region is also found as a domain in various metabolic enzymes.
Several structures of the 2Fe-2S ferredoxin domain have been determined (see for example <PDB:4FXC>) . The domain is classified as a β-grasp which is characterized as having a β-sheet comprised of four β-strands and one α-helix flanking the sheet . The two Fe atoms are coordinated tetrahedrally by the two inorganic S atoms and four cysteinyl S atoms.
Some proteins that contains a 2Fe-2S ferredoxin-type domain are listed below:
Three of the four conserved cysteines are clustered together in the same region of the protein. Our signature pattern spans that iron-sulfur binding region. We also developed a profile that covers the whole domain.Note:
Ferredoxins from the adrenodoxin subfamily are slightly divergent and are not picked up by our pattern (but they are recognized by the profile). We have thus developed a second pattern specific for this subfamily (see <PDOC00642>).Last update:
March 2005 / Text revised; profile added.
PROSITE methods (with tools and information) covered by this documentation:
|Source||Trends Ecol. Evol. 3:222-226(1988).|
|2||Authors||Harayama S. Polissi A. Rekik M.|
|Title||Divergent evolution of chloroplast-type ferredoxins.|
|Source||FEBS Lett. 285:85-88(1991).|
|3||Authors||Fukuyama K. Ueki N. Nakamura H. Tsukihara T. Matsubara H.|
|Title||Tertiary structure of [2Fe-2S] ferredoxin from Spirulina platensis refined at 2.5 A resolution: structural comparisons of plant-type ferredoxins and an electrostatic potential analysis.|
|Source||J. Biochem. 117:1017-1023(1995).|
|Source||Curr. Opin. Struct. Biol. 2:394-401(1992).|