Transition Metal Ion Homeostasis
Jessica R. Sheldon, Ronald S. Flannagan, Mélissa Hannauer and David E. Heinrichs
from: Staphylococcus: Genetics and Physiology (Edited by: Greg A. Somerville). Caister Academic Press, U.K. (2016) Pages: 171-220.
The six 3D-block transition metals - iron, manganese, zinc, nickel, cobalt, and copper are biologically relevant to both prokaryotes and eukaryotes alike, serving as essential micronutrients while at the same time being potentially toxic in excess. As such, intricate mechanisms exist to control the availability of metal ions within the human host and in bacteria, in an effort to maintain homeostatic concentrations of these elements. Perturbations to metal ion availability within the host can impact both overall health, as well as susceptibility to infectious diseases, as bacteria, such as the staphylococci, express a plethora of acquisition systems that allow for the extraction of transition metals from the environment to fulfill their nutritional requirements. The host counters this effort to acquire metals with immune mechanisms that not only actively sequester transition metals, rendering them unavailable to support microbial growth, but also that harness the destructive redox potential of copper and zinc to intoxicate invading bacteria; these processes are collectively termed nutritional immunity. Importantly, exploitation of metal acquisition pathways in the staphylococci may represent a viable option for the realization of novel antimicrobials or vaccine based therapies that are desperately needed to combat important human staphylococcal pathogens such as S. aureus read more ...