Denesyuk_2025_Molecules_30_

beta-Lactamase/transpeptidase-like superfamily proteins are serine proteases that use the Ser-Lys catalytic dyad to carry out their biological functions. Here, we investigate the three known families of beta-lactamase/transpeptidase-like superfamily proteins, beta-lactamase/D-Ala carboxypeptidase, glutaminase, and Dac-like, and describe the structural catalytic cores that govern the catalytic residues in these proteins. We show that the structural catalytic core of these proteins is a combination of three zones, the mutual three-dimensional arrangement of which correspondingly determines their belonging to one of seven and twenty-four established groups and subgroups.