Autolysin

Autolysin is a general term for a family of endogenous lytic enzymes found in bacteria that hydrolyze bonds within the peptidoglycan layer of their own cell walls. These enzymes are essential for normal bacterial physiology—enabling processes such as cell growth, division, separation of daughter cells after mitosis, peptidoglycan turnover during elongation or repair, biofilm formation/dispersal, competence development in some species, and programmed autolysis. There are multiple types of autolysins classified by their cleavage sites within the peptidoglycan matrix—including N-acetylglucosaminidases (e.g., LytD/CwlG), muramidases/lysozymes, acetyl-muramyl-L-alanine amidases (e.g., LytC/CwlB), and endopeptidases. Autolysins are present in all bacteria with a peptidoglycan-based cell wall but have been most studied in Gram-positive organisms like Staphylococcus aureus and Bacillus subtilis. Their activity is tightly regulated because uncontrolled action can lead to self-destruction. Inhibitors targeting these enzymes—such as complestatin or corbomycin—bind to either the enzyme itself or its substrate within the bacterial cell wall to prevent necessary remodeling steps; this results in inhibition of bacterial growth or survival. Because autolysins play roles both in normal physiology and virulence/pathogenicity—including biofilm development—they represent promising targets for novel antibacterial therapies designed either to kill pathogens directly or disrupt persistent infections associated with biofilms.

Other names

Autolysinsbacterial autolysinAtl (gene)AtlA (Staphylococcus aureus)LytD (CwlG)LytC (CwlB)N-acetylglucosaminidasemuramidaseacetyl-muramyl-L-alanine amidaseendopeptidase

Inhibition of autolysin activity prevents peptidoglycan remodeling in bacteria by binding to the cell wall substrate or directly inhibiting the enzyme’s catalytic domain; this blocks cell division and leads to bacteriostasis or death.