InterPro: IPR001586 Beta-lactamase, class C active site

This active site signature detects all class C Beta-lactamases. The class C beta-lactamases are serine hydrolases belonging to MEROPS peptidase family S12 (D-Ala-D-Ala carboxypeptidase B family, clan SE). They are classed as non-peptidase homologues.

Beta-lactamases (EC:3.5.2.6) [1, 2] are enzymes which catalyse the hydrolysis of an amide bond in the beta-lactam ring of antibiotics belonging to the penicillin/cephalosporin family. Four kinds of beta-lactamase have been identified [3]. Class-B enzymes are zinc containing proteins whilst class -A, C and D enzymes are serine hydrolases. The three classes of serine beta-lactamases are evolutionary related and belong to a superfamily [4] that also includes DD-peptidases and a variety of other penicillin-binding proteins (PBP's). All these proteins contain a Ser-x-x-Lys motif, where the serine is the active site residue. Although clearly homologous, the sequences of the three classes of serine beta-lactamases exhibit a large degree of variability and only a small number of residues are conserved in addition to the catalytic serine.