Cell wall formation. Catalyzes the addition of glutamate to the nucleotide precursor UDP-N-acetylmuramoyl-L-alanine (UMA). ATP + D-glutamate + UDP-N-acetyl-alpha-D-muramoyl-L-alanine = ADP + H(+) + phosphate + UDP-N-acetyl-alpha-D-muramoyl-L-alanyl-D-glutamate Cell wall biogenesis; peptidoglycan biosynthesis. Belongs to the MurCDEF family.