Protein trafficking across the cell envelope of gram-positive bacteria.

Protein trafficking from the cytosol to specific sites of action is a fundamental process for bacterial survival and growth. In the monoderm gram-positive bacteria, this process involves traversing the cytoplasmic membrane, the membrane-wall interface, and the thick cell wall. With a primary focus on Bacillus subtilis and Staphylococcus aureus, this minireview aims to provide an overview and mechanistic insights into (i) protein translocation across the cytoplasmic membrane via the Sec system, (ii) protein processing by chaperones and proteases in the membrane-wall interface, and (iii) protein attachment to the cell wall and translocation across the cell wall. Furthermore, we emphasize recent advancements in spatial regulation of protein translocation systems. By examining conserved and unique mechanistic features, this review aims to offer a systematic understanding of protein trafficking in gram-positive bacteria.