Reaction: (1) protoheme + 3 reduced acceptor + 3 O2 = biliverdin-IX-δ + CO + Fe2+ + 3 acceptor + 3 H2O
(2) protoheme + 3 reduced acceptor + 3 O2 = biliverdin-IX-β + CO + Fe2+ + 3 acceptor + 3 H2O
For diagram of reaction click here
Glossary: biliverdin-IX-β = 3,7-bis(2-carboxyethyl)-2,8,12,17-tetramethyl-13,18-divinylbilin-1,19(21H,24H)-dione
biliverdin-IX-δ = 3,7-bis(2-carboxyethyl)-2,8,13,18-tetramethyl-12,17-divinylbilin-1,19(21H,24H)-dione
Other name(s): pigA (gene name)
Systematic name: protoheme,donor:oxygen oxidoreductase (biliverdin-IX-β and δ-forming)
Comments: The enzyme, characterized from the bacterium Pseudomonas aeruginosa, differs from EC 1.14.15.20, 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: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Ratliff, M., Zhu, W., Deshmukh, R., Wilks, A. and 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 (2001) 6394-6403. [PMID: 11591684]
2. Caignan, G.A., Deshmukh, R., Wilks, A., Zeng, Y., Huang, H.W., Moenne-Loccoz, P., Bunce, R.A., Eastman, M.A. and Rivera, M. Oxidation of heme to β- and δ-biliverdin by Pseudomonas aeruginosa heme oxygenase as a consequence of an unusual seating of the heme. J. Am. Chem. Soc. 124 (2002) 14879-14892. [PMID: 12475329]
3. Friedman, J., Lad, L., Li, H., Wilks, A. and Poulos, T.L. Structural basis for novel δ-regioselective heme oxygenation in the opportunistic pathogen Pseudomonas aeruginosa. Biochemistry 43 (2004) 5239-5245. [PMID: 15122889]