This is the catalytic domain of class A beta-lactamases [1]. It is closely related to Beta-lactamase, Pfam:PF00144, the serine beta-lactamase-like superfamily, which contains the distantly related Pfam:PF00905 and PF00768 D-alanyl-D-alanine carboxype ...
This is the catalytic domain of class A beta-lactamases [1]. It is closely related to Beta-lactamase, Pfam:PF00144, the serine beta-lactamase-like superfamily, which contains the distantly related Pfam:PF00905 and PF00768 D-alanyl-D-alanine carboxypeptidase.
The Class A Beta lactamase acts to hydrolyse the endocyclic amide bond of beta-lactam substrates in a two step mechanism: acylation (covalent attachment of the beta-lactam to an active site serine, Ser70), followed by deacylation. The TEM-type are the most prevalent beta-lactamases in enterobacteria and confer resistance to penicillins and cephalosporins in these species.
TEM-3 and TEM-4 are capable of hydrolyzing cefotaxime and ceftazidime. TEM-5 is capable of hydrolysing ceftazidime. TEM-6 is capable of hydrolysing ceftazidime and aztreonam. TEM-8/CAZ-2, TEM-16/CAZ-7 and TEM-24/CAZ-6 are markedly active against ceftazidime. IRT-4 shows resistance to beta-lactamase inhibitors.
Defined by 6 residues: SER:A-45 [auth A-70]LYS:A-48 [auth A-73]SER:A-105 [auth A-130]GLU:A-141 [auth A-166]LYS:A-209 [auth A-234]ALA:A-212 [auth A-237]