Fortifying the wall: synthesis, regulation and degradation of bacterial peptidoglycan

•PBPs utilize the PG precursor molecule (lipid II) to add new material to the growing sacculus.•PG synthesis is tightly regulated at multiple levels.•Bacteria have evolved key PG modifications to evade the host immune system.•Bacteria have a variety of PG hydrolases, which are essential for bacterial cell morphogenesis.•Robust PG recycling pathways enable released murein components to re-enter the PG biosynthetic pathway. Growth and maintenance of the protective peptidoglycan cell wall are vital to bacterial growth and morphogenesis. Thus, the relative rate and spatiotemporal control of the synthesis and degradation of this net-like polymer defines bacterial cell shape. In recent years, our understanding of the processes that govern this delicate metabolic balance has improved and should lend insight into how to therapeutically target the system in the future.