Biochemical characterization of protoporphyrinogen dehydrogenase and protoporphyrin ferrochelatase of Vibrio vulnificus and the critical complex formation between these enzymes

Both proteobacteria and eukaryotes have evolved mechanisms to prevent the harmful accumulation of the heme biosynthesis intermediate PPn. The data presented here suggest two previously unknown mechanisms: the channeling of PPn through the PgdH1-PpfC complex, and the direct inhibition of PgdH1 activity (PgoX activity as well) by heme.