Removes C-terminal D-alanyl residues from sugar-peptide cell wall precursors. Preferential cleavage: (Ac)2-L-Lys-D-Ala-|-D-Ala. Also transpeptidation of peptidyl-alanyl moieties that are N-acyl substituents of D-alanine. Cell wall biogenesis; peptidoglycan biosynthesis. Belongs to the peptidase S11 family.