M20 Peptidase T like enzymes specifically cleave tripeptides
Peptidase M20 family, PeptT (tripeptide aminopeptidase; tripeptidase)-like subfamily. This group includes bacterial tripeptidases as well as predicted tripeptidases. Peptidase T acts only on tripeptide substrates, and is thus called a tripeptidase. It catalyzes the release of N-terminal amino acids with hydrophobic side chains from tripeptides with high specificity; dipeptides, tetrapeptides or tripeptides with the N-terminus blocked are not cleaved. Tripeptidases are known to function at the final stage of proteolysis in lactococcal bacteria and release amino acids from tripeptides produced during the digestion of milk proteins such as casein.
Jiyao W et al.(2023). "The conserved domain database in 2023.",