FIGURE 3.

Profile of L. monocytogenes surface proteins identified by proteomics in the cell wall of intracellular and extracellular bacteria. Cell wall extracts were prepared from intracellular bacteria after 6 h post-infection of JEG-3 epithelial cells or from extracellular bacteria grown in BHI or minimal medium IMM to stationary phase. These extracts were processed for high resolution MS to identify proteins associated with the peptidoglycan. Indicated is the coverage obtained in the three conditions (intracellular, BHI, and IMM) for surface proteins covalently bound to the peptidoglycan, including members of the LPXTG family and the two sortase-B (SrtB) substrates Lmo2185 and Lmo2186. The PrfA-regulated proteins ActA and LLO are also shown. LPXTG proteins with differential expression in some of the conditions tested are shown as gray bars and those identified with a high coverage in the three experimental conditions as hatched bars. InlA and ActA are highlighted as black bars.