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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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"The coordination of heme uptake and synthesis in mycobacteria" by Rebecca Donegan
Iron is necessary for the survival of most pathogens. In the human host, iron is extremely limited and the vast majority of bioavailable iron is found as heme-iron. Infectious mycobacteria, like Mycobacterium tuberculosis (Mtb), have evolved pathways to use heme from the host as an iron source. Mtb can also synthesize heme de novo, and since heme is both necessary and cytotoxic, Mtb must regulate uptake and synthesis to maintain heme homeostasis, however how Mtb regulates heme uptake and whether host derived heme can be utilized directly by Mtb is not known. Our work shows that, the terminal heme synthesis enzyme in Mtb, coproheme decarboxylase (ChdC), has a second role in coordinating heme uptake in both Mtb and the nontuberculous mycobacterium, Mycobacterium smegmatis (Msm). Furthermore, we have found that ChdC expression is regulated in an iron dependent manner, suggesting a role for ChdC in regulating heme uptake in response to iron availability. The regulation of heme uptake by ChdC may be important for survival of mycobacteria in the host and could prove a useful target for anti-mycobacterial drugs.