A Molecular Mechanism for Bacterial Susceptibility to Zinc
Christopher A McDevitt, Abiodun D Ogunniyi, Eugene Valkov, Michael C Lawrence, Bostjan Kobe, Alastair G McEwan, James C Paton
PLOS PATHOGENS | PUBLIC LIBRARY SCIENCE | Published : 2011
Transition row metal ions are both essential and toxic to microorganisms. Zinc in excess has significant toxicity to bacteria, and host release of Zn(II) at mucosal surfaces is an important innate defence mechanism. However, the molecular mechanisms by which Zn(II) affords protection have not been defined. We show that in Streptococcus pneumoniae extracellular Zn(II) inhibits the acquisition of the essential metal Mn(II) by competing for binding to the solute binding protein PsaA. We show that, although Mn(II) is the high-affinity substrate for PsaA, Zn(II) can still bind, albeit with a difference in affinity of nearly two orders of magnitude. Despite the difference in metal ion affinities, ..View full abstract
This research was funded by the National Health and Medical Research Council (NHMRC) of Australia. BK was an Australian Research Council Federation Fellow and is a NHMRC Research Fellow; JCP is a NHMRC Australia Fellow. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.