In enzymology, a phycoerythrobilin:ferredoxin oxidoreductase (EC 1.3.7.3) is an enzyme that catalyzes the chemical reaction

(3Z)-phycoerythrobilin + oxidized ferredoxin ${\displaystyle \rightleftharpoons }$ 15,16-dihydrobiliverdin + reduced ferredoxin

Thus, the two substrates of this enzyme are (3Z)-phycoerythrobilin and oxidized ferredoxin, whereas its two products are 15,16-dihydrobiliverdin 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)-phycoerythrobilin:ferredoxin oxidoreductase. This enzyme is also called PebB. This enzyme participates in porphyrin and chlorophyll metabolism.

• 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.