title: Ferrochelatase activity and protoporphyrin IX utilization in Haemophilus influenzae.
abstract: Previous research showed that the heme-requiring human pathogen Haemophilus influenzae lacks the first six of the seven enzymes required for heme synthesis, starting with the precursor, 5-amino levulinic acid. In this study, I demonstrated either directly or by reasonable inference that all 57 strains of H. influenzae examined, including 2 unable to grow on protoporphyrin IX, possess ferrochelatase, which catalyzes heme formation by insertion of Fe2+ into the protoporphyrin IX nucleus and which is the last enzyme in the heme synthetic pathway. Further, I showed that this enzyme can also function in the reverse direction, releasing Fe2+ from heme.
authors.affiliation: University of Rochester Medical Center, New York 14642, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Loeb
mesh_terms: D005294:Ferrochelatase / Q000378:metabolism*; D006193:Haemophilus influenzae / Q000201:enzymology / Q000378:metabolism*; D011524:Protoporphyrins / Q000378:metabolism*
chemical_list: D011524:Protoporphyrins; C028025:protoporphyrin IX; D005294:Ferrochelatase