Autolysins exist in all bacteria containing peptidoglycan. The peptidoglycan matrix is very rigid, so these enzymes break down the peptidoglycan matrix in small sections so that growth and division of cells can occur. Autolysins do this by hydrolyzing the β-(1,4) bond between N-acetylmuramic acid and N-acetylglucosamine molecules. Autolysins are naturally produced by peptidoglycan containing bacteria, but excessive amounts will degrade the peptidoglycan matrix and cause the cell to burst due to osmotic pressure. Gram-positive bacteria regulate autolysins with teichoic acid molecules attached to the tetrapeptide of the peptidoglycan matrix.