Penicillin-binding protein. Has low DD-carboxypeptidase activity. Preferential cleavage: (Ac)2-L-Lys-D-Ala-|-D-Ala. Also transpeptidation of peptidyl-alanyl moieties that are N-acyl substituents of D-alanine. Not essential for cell growth. Belongs to the peptidase S12 family. YfeW subfamily.