Figure 6. Mammalian PGRPs exploit bacterial defense mechanism to kill bacteria.
In Gram-positive bacteria PGRPs bind to peptidoglycan in bacterial cell wall at the cell separation sites (the sites of hydrolysis by LytE and LytF, which in B. subtilis are the enzymes that separate daughter cells after cell division). PGRPs then activate CssR-CssS two-component system that senses extracytoplasmic misfolded proteins. CssR-CssS triggers membrane depolarization and •OH production, which results in inhibition of macromolecule synthesis and bacterial death.