The lipid II isoglutaminyl synthase complex catalyzes the formation of alpha-D-isoglutamine in the cell wall lipid II stem peptide (PubMed:22303291). The MurT subunit catalyzes the ATP-dependent amidation of D-glutamate residue of lipid II, converting it to an isoglutamine residue (By similarity). ATP + beta-D-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)-di-trans,octa-cis-undecaprenyl diphosphate + H2O + L-glutamine = ADP + beta-D-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-D-isoglutaminyl-L-Lys-D-Ala-D-Ala)-di-trans,octa-cis-undecaprenyl diphosphate + H(+) + L-glutamate + phosphate ATP + beta-D-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)-di-trans,octa-cis-undecaprenyl diphosphate = ADP + beta-D-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-O-P-Glu-L-Lys-D-Ala-D-Ala)-di-trans,octa-cis-undecaprenyl diphosphate beta-D-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-O-P-Glu-L-Lys-D-Ala-D-Ala)-di-trans,octa-cis-undecaprenyl diphosphate + NH4(+) = beta-D-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-D-isoglutaminyl-L-Lys-D-Ala-D-Ala)-di-trans,octa-cis-undecaprenyl diphosphate + H(+) + phosphate Cell wall biogenesis; peptidoglycan biosynthesis. Forms a heterodimer with GatD. The gatD-murT double mutant shows abnormal peptidoglycan composition, with decreased amidation of the glutamate residue. The mutant has a normal morphology but growth rate is greatly reduced. Mutant shows reduced antibiotic resistance and increased sensitivity to lysozyme. Belongs to the MurCDEF family. MurT subfamily.