How is peptidoglycan formed?

Peptidoglycan forms the outermost cell wall in almost all bacteria. It is comprised of glycosaminoglycan chains interlinked with short peptides and is present as a rigid sac completely surrounding the outside of the cytoplasmic membrane.

Peptidoglycan is formed through a complex biological process that involves a number of enzyme reactions that occur in multiple locations. Peptidoglycan formation is initiated in the cytoplasm with the synthesis of nucleotide precursors. It then continues with the synthesis of lipid-linked intermediates that occurs on the inner side of the cytoplasmic membrane. The final step involves polymerization reactions that occur in the periplasmic space. In this step, the precursor is polymerized into the peptidoglycan layer.