A Bacillus anthracis system for acquisition of heme-bound iron

In Bacillus anthracis, an alternative to the use of chelating agents (siderophores) for acquiring iron consists in using a system of hemophores and transporter proteins for scavenging hemes from hemoglobin and delivering them into the bacterial cell. B. anthracis utilizes the siderophore-mediated mechanism of acquiring iron predominantly at the intracellular stage of its development, with the system of hemophores and transporter proteins being used at the extracellular stage of anthrax infection. The structure, genetic organization, and functions of the system for heme iron acquisition in B. anthracis, understanding of which may facilitate the development of new therapies for anthrax, are discussed.