Catalyzes the addition of both L- and D-lysine to the nucleotide precursor UDP-N-acetylmuramoyl-L-alanyl-D-glutamate (UMAG) in the biosynthesis of bacterial cell-wall peptidoglycan. Is also able to use meso-diaminopimelate as the amino acid substrate in vitro, although much less efficiently. ATP + L-lysine + UDP-N-acetyl-alpha-D-muramoyl-L-alanyl-D-glutamate = ADP + H(+) + phosphate + UDP-N-acetyl-alpha-D-muramoyl-L-alanyl-gamma-D-glutamyl-L-lysine ATP + D-lysine + UDP-N-acetyl-alpha-D-muramoyl-L-alanyl-D-glutamate = ADP + H(+) + N(6)-(UDP-N-acetyl-alpha-D-muramoyl-L-alanyl-gamma-D-glutamyl)-D-lysine + phosphate The catalytic efficiency for the L-lysine adding activity is 4-fold and 10-fold higher than that for the D-lysine and meso-diaminopimelate adding activity, respectively. Optimum pH is 9.4 for the L-lysine adding activity. Optimum temperature is 68 degrees Celsius for the L-lysine adding activity. Cell wall biogenesis; peptidoglycan biosynthesis. Carboxylation is probably crucial for Mg(2+) binding and, consequently, for the gamma-phosphate positioning of ATP. The peptidoglycan of T.maritima was shown to contain approximate amounts of both enantiomers of lysine and no diaminopimelate. Belongs to the MurCDEF family. MurE subfamily.