Reaction: 2 reduced ferredoxin + thioredoxin disulfide = 2 oxidized ferredoxin + thioredoxin + 2 H+
Systematic name: ferredoxin:thioredoxin disulfide oxidoreductase
Comments: The enzyme contains a [4Fe-4S] cluster and internal disulfide. It forms a mixed disulfide with thioredoxin on one side, and docks ferredoxin on the other side, enabling two one-electron transfers. The reduced thioredoxins generated by the enzyme activate the Calvin cycle enzymes EC 184.108.40.206 (fructose-bisphosphatase), EC 220.127.116.11 (sedoheptulose-bisphosphatase) and EC 18.104.22.168 (phosphoribulokinase) as well as other chloroplast enzymes by disulfide reduction.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
1. Buchanan, B.B. Regulation of CO2 assimilation in oxygenic photosynthesis: the ferredoxin/thioredoxin system. Perspective on its discovery, present status, and future development. Arch. Biochem. Biophys. 288 (1991) 1-9. [PMID: 1910303]
2. Chow, L.P., Iwadate, H., Yano, K., Kamo, M., Tsugita, A., Gardet-Salvi, L., Stritt-Etter, A.L. and Schurmann, P. Amino acid sequence of spinach ferredoxin:thioredoxin reductase catalytic subunit and identification of thiol groups constituting a redox-active disulfide and a [4Fe-4S] cluster. Eur. J. Biochem. 231 (1995) 149-156. [PMID: 7628465]
3. Staples, C.R., Ameyibor, E., Fu, W., Gardet-Salvi, L., Stritt-Etter, A.L., Schurmann, P., Knaff, D.B. and Johnson, M.K. The function and properties of the iron-sulfur center in spinach ferredoxin: thioredoxin reductase: a new biological role for iron-sulfur clusters. Biochemistry 35 (1996) 11425-11434. [PMID: 8784198]