sentence: This finding was recently confirmed and the exact target of colicin M was identified ; colicin M is a phosphatase that cleaves the phosphate bond between the lipid moiety and the pyrophosphoryl group of lipid II ( El Ghachi et al ., 2006 ) , forming 1-pyrophospho-N-acetyl-muramyl pentapeptide-N-acetyl-glucosamine and undecaprenol instead of undecaprenol pyrophosphate ; undecaprenol does not enter the murein biosynthesis cycle.Colicin M , like other colicins , is only bactericidal when provided from outside cells ( Harkness and Braun , 1990 ) because it has access to the target only while entering the cells .