title: An Essential Factor for High Mg2+Tolerance ofStaphylococcus aureus.
abstract: 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 aureushas 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 fromSalmonellaand 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.
authors.affiliation: Department of Microbiology and Molecular Medicine, CMU Faculty of Medicine, University of Geneva Geneva, Switzerland.
authors.forename: Joshua
authors.initials: J
authors.lastname: Armitano
authors.affiliation: Department of Microbiology and Molecular Medicine, CMU Faculty of Medicine, University of Geneva Geneva, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Redder
authors.affiliation: Department of Microbiology and Molecular Medicine, CMU Faculty of Medicine, University of Geneva Geneva, Switzerland.
authors.forename: Vanessa A
authors.initials: VA
authors.lastname: Guimarães
authors.affiliation: Department of Microbiology and Molecular Medicine, CMU Faculty of Medicine, University of Geneva Geneva, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Linder
keywords: CBS; CNNM; CorB; CorC; MpfA; Staphylococcus aureus; magnesium tolerance