Fig. 6: The secretion of non-covalently surface-bound proteins in USA300.

a Most abundant non-covalent proteins on the surface of USA300 identified by mass spectrometry. Proteins with average peptide spectrum matches (PSMs) > 50 are shown here. Circles represent the PSMs of proteins on the USA300 surface (left axis). The PSMs of these proteins in the culture supernatant identified in a previous study²⁷ are shown in bars (right axis). Data show mean ± SEM of 3 independent samples. The color bars below indicate the localization of each protein predicted by PSORTb. * Sbi and Hel have equal prediction scores localized to the membrane, cell wall, or extracellular. † Data for secreted Map is not available. In Chapman et al., data were searched against a USA300_FPR3757 proteome database where Map protein is not present. b Representative immunoblot (top) and quantification (bottom) of His-tagged IsaB in indicated fractions in WT and the mprF mutant (left) or the yfpP mutant (right) from 6 independent experiments. *, protein marker of 17 kD. c Representative immunoblot (top) and quantification (bottom) of His-tagged Hel in indicated fractions in WT and the mprF mutant from 4 independent experiments. *, protein marker of 34 kD. d Representative immunoblot (top) and quantification (bottom) of His-tagged ScaH in indicated fractions in WT and the yfpP mutant from 7 independent experiments. *, protein marker of 95 kD. e Representative immunoblot (top) and quantification (bottom) of His-tagged proGeh and Geh in indicated fractions in WT and the yfpP mutant from 6 independent experiments. *, protein marker of 95 kD. †, protein marker of 43 kD. b–e Each dot is an independent experiment. The protein signals were normalized against 50 ng purified His-tagged LukAB in each experiment. The p-values were determined by two-tailed paired t tests. Source data are provided as a Source Data file.