Membrane-bound lytic endotransglycosylase in Escherichia coli.

摘要: The gene for a novel endotype membrane-bound lytic transglycosylase, emtA , was mapped at 26.7 min of the E. coli chromosome. EmtA is lipoprotein with an apparent molecular mass 22 kDa. Overexpression did not result in bacteriolysis vivo, but enzyme shown to hydrolyze glycan strands isolated from murein by amidase treatment. formation tetra- and hexasaccharides, no disaccharides, reflects endospecificity enzyme. products are characterized presence 1,6-anhydromuramic acid, indicating transglycosylase reaction mechanism. may function as formatting that trims nascent produced synthesis machinery into proper sizes, or it be involved tightly controlled minor holes sacculus facilitate export bulky compounds across barrier.