Altered muropeptide composition in Staphylococcus aureus strains with an inactivated femA locus.

ABSTRACT

Tn551 inactivation of femA, a factor involved in methicillin resistance of Staphylococcus aureus, caused the production of peptidoglycan in which the fraction of monoglycyl- and serine-containing muropeptides was increased at the expense of pentaglycyl muropeptides. femA mutants have a specific block in the biosynthesis of pentaglycine cross bridges after the addition of the first glycine residue.