Analysis of the murein of a Listeria monocytogenes EGD mutant lacking functional penicillin binding protein 5 (PBP5).

Cells of a mutant of Listeria monocytogenes lacking functional PBP5, an enzyme with DD-carboxypeptidase activity, make thicker cells walls. In this study we show that the muropeptide profile of the mutant, obtained after HPLC analysis of a muramidase digest of cell wall murein, differs from that for the wild type strain. The main differences embrace strongly reduced disaccharide-tripeptide content, strongly increased amounts of pentapeptide-containing muropeptides and a shift in profile from less cross-linked muropeptides (monomers, dimers) towards more highly cross-linked ones.