An essential factor for high Mg2+ tolerance of Staphylococcus aureus

• Main Authors: Joshua Armitano, Peter Redder, Vanessa Andrade Guimaraes, Patrick Linder
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2016-11-01
• Series: Frontiers in Microbiology
• Subjects: Staphylococcus aureus; CBS; MPFA; CORB; CORC; CNNM
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fmicb.2016.01888/full

Internal bacterial concentration of Mg2+, the most abundant divalent cation in living cells, is estimated to be in the single millimolar range. However, many bacteria will thrive in media with only micromolars of Mg2+, by using a range of intensely studied and highly efficient import mechanisms, as well as in media with very high magnesium concentration, presumably mediated by currently unknown export mechanisms. Staphylococcus aureus has a particularly high Mg2+ tolerance for a pathogen, growing unimpaired in up to 770 mM Mg2+, and we here identify SA0657, a key factor in this tolerance. The predicted domain structure of SA0657 is shared with a large number of proteins in bacteria, archaea and even eukarya, for example CorB from Salmonella and the human CNNM protein family. One of the shared domains, a CBS pair potentially involved in Mg2+ sensing, contains the conserved Glycine326 which we establish to be a key residue for SA0657 function. In light of our findings, we propose the name MpfA, Magnesium Protection Factor A, for SA0657.