HO1 and PcyA proteins involved in phycobilin biosynthesis form a 1:2 complex with ferredoxin-1 required for photosynthesis

FEBS Lett. 2009 Apr 17;583(8):1251-6. doi: 10.1016/j.febslet.2009.03.052. Epub 2009 Mar 27.


The HO1 and PcyA genes, encoding heme oxygenase-1 (HO1) and phycocyanobilin (PCB):ferredoxin (Fd) oxidoreductase (PcyA), respectively, are required for chromophore synthesis in photosynthetic light-harvesting complexes, photoreceptors, and circadian clocks. In the PCB biosynthetic pathway, heme first undergoes cleavage to form biliverdin. I confirmed that Fd1 induced the formation of a stable and functional HO1 complex by the gel mobility shift assay. Furthermore, analysis by a chemical cross-linking technique designed to detect protein-protein interactions revealed that HO1 and PcyA directly interact with Fd in a 1:2 ratio. Thus, Fd1, a one-electron carrier protein in photosynthesis, drives the phycobilin biosynthetic pathway.

MeSH terms

  • Chromatography, Gel
  • Electrophoretic Mobility Shift Assay
  • Ferredoxins / metabolism*
  • Genes, Bacterial
  • Heme Oxygenase (Decyclizing) / genetics
  • Heme Oxygenase (Decyclizing) / metabolism
  • Heme Oxygenase (Decyclizing) / physiology*
  • Oxidoreductases / genetics
  • Oxidoreductases / metabolism
  • Oxidoreductases / physiology*
  • Photosynthesis*
  • Phycobilins / biosynthesis*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification


  • Ferredoxins
  • Phycobilins
  • Recombinant Proteins
  • Oxidoreductases
  • Heme Oxygenase (Decyclizing)
  • phycocyanobilin-ferredoxin oxidoreductase, Anabaena