Impact of peptidoglycan O-acetylation on autolytic activities of the Enterococcus faecalis N-acetylglucosaminidase AtlA and N-acetylmuramidase AtlB.
Autolysins are potentially lethal enzymes that partially hydrolyze peptidoglycan for incorporation of new precursors and septum cleavage after cell division.  Here, we explored the impact of peptidoglycan O-acetylation on the enzymatic activities of Enterococcus faecalis major autolysins, the N-acetylglucosaminidase AtlA and the N-acetylmuramidase AtlB. We constructed isogenic strains with various O-acetylation levels and used them as substrates to assay E. faecalis autolysin activities.  Peptidoglycan O-acetylation had a marginal inhibitory impact on the activities of these enzymes.  In contrast, removal of cell wall glycopolymers increased the AtlB activity (37-fold), suggesting that these polymers negatively control the activity of this enzyme.