EC - Heme oxygenase (biliverdin-IX-β and δ-forming)

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IntEnz Enzyme Nomenclature


Accepted name:
heme oxygenase (biliverdin-IX-β and δ-forming)
Other name:
pigA (gene name)
Systematic name:
protoheme,donor:oxygen oxidoreductase (biliverdin-IX-β and δ-forming)



The enzyme, characterized from the bacterium Pseudomonas aeruginosa, differs from EC, heme oxygenase (biliverdin-producing, ferredoxin), in that the heme substrate is rotated by approximately 110 degrees within the active site, resulting in cleavage at a different part of the ring. It forms a mixture of about 70% biliverdin-IX-δ and 30% biliverdin-IX-β.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB


  1. Ratliff, M., Zhu, W., Deshmukh, R., Wilks, A., Stojiljkovic, I.
    Homologues of neisserial heme oxygenase in gram-negative bacteria: degradation of heme by the product of the pigA gene of Pseudomonas aeruginosa.
    J. Bacteriol. 183: 6394-6403 (2001). [PMID: 11591684]
  2. Caignan, G. A., Deshmukh, R., Wilks, A., Zeng, Y., Huang, H. W., Moenne-Loccoz, P., Bunce, R. A., Eastman, M. A., Rivera, M.
    Oxidation of heme to beta- and delta-biliverdin by Pseudomonas aeruginosa heme oxygenase as a consequence of an unusual seating of the heme.
    J. Am. Chem. Soc. 124: 14879-14892 (2002). [PMID: 12475329]
  3. Friedman, J., Lad, L., Li, H., Wilks, A., Poulos, T. L.
    Structural basis for novel delta-regioselective heme oxygenation in the opportunistic pathogen Pseudomonas aeruginosa.
    Biochemistry 43: 5239-5245 (2004). [PMID: 15122889]

[EC created 2017]