Involved in the biosynthesis of porphyrin-containing compound. Binds 1 [4Fe-4S] cluster. The cluster is coordinated with 3 cysteines and an exchangeable S-adenosyl-L-methionine. Porphyrin-containing compound metabolism; protoporphyrin-IX biosynthesis. Induced under anaerobic conditions and by hydrogen peroxide stress. It is also dependent on induction by ResDE, Fnr and ArfM. Cells lacking this gene accumulate coproporphyrin-III only under anaerobic conditions, however no obvious respiratory growth phenotype is observed under anaerobic conditions. The hemN hemZ double mutant do not abolish aerobic and anaerobic respiratory growth, however a reduction of growth is observed. HemZ is able to complement a S.typhimurium hemF hemN double mutant under aerobic and anaerobic conditions, however under anaerobic growth conditions, the double mutant complemented with hemZ grows significantly faster. Belongs to the anaerobic coproporphyrinogen-III oxidase family. HemZ subfamily. Although the enzyme shows to be able to complement hemF hemN double mutant and to accumulate coproporphyrinogen-III when the gene is disrupted, no oxygen-independent coproporphyrinogen-III oxidase activity has been shown. The exact role of this protein is still unknown.