Hydrolyzes N-terminal residues in D-amino acid-containing peptides. Release of an N-terminal D-amino acid from a peptide, Xaa-|-Yaa-, in which Xaa is preferably D-Ala, D-Ser or D-Thr. D-amino acid amides and methyl esters also are hydrolyzed, as is glycine amide. Inhibited by beta-lactam compounds such as 6-aminopenicillic acid, 7-aminocephalosporanic acid, benzylpenicillin and ampicillin. Inhibited by p-chloromercuribenzoate. Optimum pH is 8.5. Optimum temperature is 45 degrees Celsius. Homodimer. Belongs to the peptidase S12 family.