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- ************************************************************
- * 2Fe-2S ferredoxins, iron-sulfur binding region signature *
- ************************************************************
-
- Ferredoxins [1] are a group of iron-sulfur proteins which mediate electron
- transfer in a wide variety of metabolic reactions. Ferredoxins can be divided
- into several subgroups depending upon the physiological nature of the iron
- sulfur cluster(s) and according to sequence similarities. One of these
- subgroups are the 2Fe-2S ferredoxins, which are proteins or domains of around
- one hundred amino acid residues that bind a single 2Fe-2S iron-sulfur cluster.
- The proteins that are known [2] to belong to this family are listed below.
-
- - Ferredoxin from photosynthetic organisms; namely plants and algae where it
- is located in the chloroplast or cyanelle; and cyanobacteria.
- - Ferredoxin from archaebacteria of the Halobacterium genus.
- - Ferredoxin IV from Rhodobacter capsulatus (gene ptfA).
- - Ferredoxin in the toluene degradation operon (gene xylT) and naphtalene
- degradation operon (gene nahT) of Pseudomonas putida.
-
- - The N-terminal domain of the bifunctional ferredoxin/ferredoxin reductase
- electron transfer component of the benzoate 1,2-dioxygenase complex (gene
- benC) from Acinetobacter calcoaceticus, the toluate 1,2-dioxygenase system
- (gene xylZ), and the xylene monooxygenase system (gene xylA) from
- Pseudomonas putida.
- - The N-terminal domain of phenol hydroxylase protein p5 (gene dmpP) from
- Pseudomonas Putida.
- - The N-terminal domain of methane monooxygenase component C (gene mmoC)
- from Methylococcus capsulatus .
- - The C-terminal domain of the vanillate degradation pathway protein vanB in
- a Pseudomonas species.
- - The N-terminal domain of bacterial fumarate reductase iron-sulfur protein
- (gene frdB).
- - The central domain of eukaryotic succinate dehydrogenase (ubiquinone) iron-
- sulfur protein.
- - The N-terminal domain of eukaryotic Xanthine dehydrogenase.
-
- In the 2Fe-2S ferredoxins, four cysteine residues bind the iron-sulfur
- cluster. Three of these cysteines are clustered together in the same region of
- the protein. Our signature pattern spans that iron-sulfur binding region.
-
- -Consensus pattern: C-{C}-{C}-[GA]-{C}-C-[GAST]-{CPDEKRHFYW}-C
- [The three C's are 2Fe-2S ligands]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: 5.
-
- -Note: in addition to the proteins listed above there are a number of other
- ferredoxin-like proteins that bind a 2Fe-2S cluster but which do not seem to
- be evolutionary related to this family. Among them are the ferredoxins from
- the adrenodoxin/putidaredoxin family (see the relevant section) as well as
- the bacterial aromatic dioxygenase systems ferredoxin-like proteins such as
- bnzC, ndoA, and todB.
-
- -Last update: June 1994 / Text revised.
-
- [ 1] Meyer J.
- Trends Ecol. Evol. 3:222-226(1988).
- [ 2] Harayama S., Polissi A., Rekik M.
- FEBS Lett. 285:85-88(1991).
-