Phycocyanobilin:ferredoxin oxidoreductase

In enzymology, a phycocyanobilin:ferredoxin oxidoreductase (PcyA, EC 1.3.7.5) is an enzyme that catalyzes the chemical reaction

(3Z)-phycocyanobilin + oxidized ferredoxin biliverdin IXalpha + reduced ferredoxin

Thus, the two substrates of this enzyme are (3Z)-phycocyanobilin and oxidized ferredoxin, whereas its two products are biliverdin IXalpha and reduced ferredoxin.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with an iron-sulfur protein as acceptor. The systematic name of this enzyme class is (3Z)-phycocyanobilin:ferredoxin oxidoreductase. This enzyme participates in porphyrin and chlorophyll metabolism.

Structural studies

As of late 2007, 3 structures have been solved for this class of enzymes, with PDB accession codes 2D1E, 2DKE, and 2G18.

References

• Frankenberg N, Mukougawa K, Kohchi T, Lagarias JC (2001). "Functional genomic analysis of the HY2 family of ferredoxin-dependent bilin reductases from oxygenic photosynthetic organisms". Plant. Cell. 13 (4): 965–78. doi:10.1105/tpc.13.4.965. PMC 135530. PMID 11283349. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=135530. 
• Beale SI (1993). "Biosynthesis of phycobilins". Chem. Rev. 93 (2): 785–802. doi:10.1021/cr00018a008. 
• Wu SH, McDowell MT, Lagarias JC (1997). "Phycocyanobilin is the natural precursor of the phytochrome chromophore in the green alga Mesotaenium caldariorum". J. Biol. Chem. 272 (41): 25700–5. doi:10.1074/jbc.272.41.25700. PMID 9325294.