A fluorescence microscopy method to directly follow the localization of defined proteins in @entity794 was hampered by the unstable fluorescence of fluorescent proteins. Here, we constructed plasmid (pCX) encoded red fluorescence (RF) mCherry ( @entity2022 ) hybrids, namely @entity2022 -cyto (no signal peptide and no sorting sequence), @entity2022 -sec (with signal peptide), and @entity2022 -cw (with signal peptide and cell wall sorting sequence). The @entity794 clones targeted @entity2022 -fusion proteins into the cytosol, the supernatant and the cell envelope respectively; in all cases mCherry exhibited bright fluorescence. In staphylococci two types of signal peptides (SP) can be distinguished: the +YSIRK motif SP(lip) and the -YSIRK motif SP(sasF). @entity2022 -hybrids supplied with the +YSIRK motif SP(lip) were always expressed higher than those with -YSIRK motif SP(sasF). To study the location of the anchoring process and also the influence of SP type, @entity2022 -cw was supplied on the one hand with +YSIRK motif ( @entity2022 -cw1) and the other hand with -YSIRK motif ( @entity2022 -cw2). @entity2022 -cw1 preferentially localized at the cross wall, while @entity2022 -cw2 preferentially localized at the peripheral wall. Interestingly, when treated with sub-lethal concentrations of @entity114 or @entity13758 , both @entity2022 -cw1 and @entity2022 -cw2 were concentrated at the cross wall. The shift from the peripheral wall to the cross wall required Sortase A (SrtA), as in the srtA mutant this effect was blunted. The effect is most likely due to antibiotic mediated increase of free anchoring sites (Lipid II) at the cross wall, the substrate of SrtA, leading to a preferential incorporation of anchored proteins at the cross wall.

Cell wall antibiotics provoke accumulation of anchored mCherry in the cross wall of XXXX .

@entity114 :: ('MESH:D010406', 'Chemical') :: ['penicillin'] @entity13758 :: ('MESH:C419802', 'Chemical') :: ['moenomycin'] @entity794 :: ('1280', 'Species') :: ['Staphylococcus', 'S. aureus'] @entity2022 :: ('104242(Tax:10090)', 'Gene') :: ['MCh', 'mCh']
@entity794 :: (1280,Species) :: ['Staphylococcus aureus']
