InterPro domain: IPR034505

Biosynthesis of heme and chlorophyll requires coproporphyrinogen III to be converted to protoporphyrinogen IX by oxidatively decarboxylating the propionate side chains of rings A and B to the corresponding vinyl group [ 1 , 2 , 3 ].

This entry includes HemN, HemW, HemZ from bacteria, and Rsad1 from animals. HemN catalyzes the anaerobic oxidative decarboxylation of propionate groups of rings A and B of coproporphyrinogen III to yield the vinyl groups in protoporphyrinogen IX [ 4 ]. HemW may act as a heme chaperone, transferring heme to an unknown acceptor [ 5 ]. HemZ is involved in the biosynthesis of porphyrin-containing compound [ 6 ].

1. Crystal structure of coproporphyrinogen III oxidase reveals cofactor geometry of Radical SAM enzymes. EMBO J. 22, 6214-24
2. Radical S-adenosylmethionine enzyme coproporphyrinogen III oxidase HemN: functional features of the [4Fe-4S] cluster and the two bound S-adenosyl-L-methionines. J. Biol. Chem. 280, 29038-46
3. Oxygen-independent coproporphyrinogen-III oxidase HemN from Escherichia coli. J. Biol. Chem. 277, 34136-42
4. L-asparaginase of Tetrahymena pyriformis is associated with a kinase activity. Mol. Cell. Biochem. 95, 77-87
5. Functional differentiation of two analogous coproporphyrinogen III oxidases for heme and chlorophyll biosynthesis pathways in the cyanobacterium Synechocystis sp. PCC 6803. Plant Cell Physiol. 51, 650-63
6. Transcriptional control of Bacillus subtilis hemN and hemZ. J. Bacteriol. 181, 5922-9