Environmental Heme Utilization by Heme-Auxotrophic Bacteria
Résumé
Heme, an iron-containing porphyrin, is the prosthetic group for numerous key cellular enzymatic and regulatory processes. Many bacteria encode the biosynthetic enzymes needed for autonomous heme production. Remarkably, however, numerous other bacteria lack a complete heme biosynthesis pathway, yet encode heme-requiring functions. For such heme-auxotrophic bacteria (HAB), heme or porphyrins must be captured from the environment. Functional studies, aided by genomic analyses, provide insight into the Hlifestyle, how they acquire and manage heme, and the uses of heme that make it worthwhile, and sometimes necessary, to capture this bioactive molecule.