InterPro: IPR000189 Prokaryotic transglycosylase, active site

Bacterial lytic transglycosylases degrade murein via cleavage of the beta-1,4- glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine, with the concomitant formation of a 1,6-anhydrobond in the muramic acid residue. Escherichia coli has at least three different lytic transglycosylases: two soluble isozymes of 65 Kd and 35 Kd and a membrane-bound enzyme of 38 Kd. The sequence of the 65 Kd enzyme (gene slt) has been determined [1]. A domain of about 90 residues located near the C-terminal section of slt was recently shown to be present in a number of other prokaryotic and phage proteins [2]. This SLT domain shared by these proteins is involved in catalytic activity. The most conserved part of this domain contains the contains two conserved serines and a glutamate which form part of this active site signature [3, 4].