This family contains a number of related ligase enzymes which have EC numbers 6.3.2.*. This family includes: MurC (Swiss:P17952), MurD (Swiss:P14900), MurE (Swiss:P22188), MurF (Swiss:P11880), Mpl (Swiss:P37773) and FolC (Swiss:P08192). MurC, MurD, Mure and MurF catalyse consecutive steps in the synthesis of peptidoglycan. Peptidoglycan consists of a sheet of two sugar derivatives, with one of these N-acetylmuramic acid attaching to a small pentapeptide. The pentapeptide is is made of L-alanine, D-glutamic acid, Meso-diaminopimelic acid and D-alanyl alanine. The peptide moiety is synthesised by successively adding these amino acids to UDP-N-acetylmuramic acid. MurC transfers the L-alanine, MurD transfers the D-glutamate, MurE transfers the diaminopimelic acid, and MurF transfers the D-alanyl alanine. This family also includes Folylpolyglutamate synthase that transfers glutamate to folylpolyglutamate.

1: Crystal structure of UDP-N-acetylmuramoyl-L-alanine:D-glutamate ligase from Escherichia coli. Bertrand JA, Auger G, Fanchon E, Martin L, Blanot D, van Heijenoort J, Dideberg O; EMBO J 1997;16:3416-3425. PMID:9218784