Received: 20 February 2018 | Revised: 13 April 2018 | Accepted: 7 May 2018 DOI: 10.1002/mbo3.669 ORIGINAL ARTICLE Bacteroides fragilis requires the ferrous- iron transporter FeoAB and the CobN- like proteins BtuS1 and BtuS2 for assimilation of iron released from heme Edson R. Rocha1 | Hector A. Bergonia2 | Svetlana Gerdes3 | Charles Jeffrey Smith1 1Department of Microbiology and Immunology, Brody School of Medicine, Abstract Greenville, North Carolina The intestinal commensal and opportunistic anaerobic pathogen Bacteroides fragilis 2 Iron and Heme Core, Division of has an essential requirement for both heme and free iron to support growth in ex- Hematology, University of Utah School of Medicine, Salt Lake City, Utah traintestinal infections. In the absence of free iron, B. fragilis can utilize heme as the 3Fellowship for Interpretation of Genomes, sole source of iron. However, the mechanisms to remove iron from heme are not Burr Ridge, Illinois completely understood. In this study, we show that the inner membrane ferrous iron Correspondence transporter ∆feoAB mutant strain is no longer able to grow with heme as the sole Edson R. Rocha, Department of source of iron. Genetic complementation with the feoAB gene operon completely Microbiology and Immunology, Brody School of Medicine, East Carolina University, restored growth. Our data indicate that iron is removed from heme in the periplasmic Biotechnology Bldg., Room 130, 600 Moye space, and the released iron is transported by the FeoAB system. Interestingly, when Blvd., Greenville, NC 27834. Email:
[email protected] B. fragilis utilizes iron from heme, it releases heme- derived porphyrins by a deche- latase activity which is upregulated under low iron conditions.