TEM beta-lactamase (TEM)

TEM beta-lactamase is a plasmid-encoded enzyme primarily found in Gram-negative bacteria, such as Escherichia coli and Haemophilus influenzae, where it serves as a major mechanism of resistance against penicillin-group antibiotics (UniProt P62593). As a member of the Ambler Class A serine beta-lactamases, the enzyme utilizes a catalytic serine residue to nucleophilically attack and hydrolyze the beta-lactam ring, rendering the antibiotic inactive (Bush & Jacoby, 2010). Since the discovery of the prototype TEM-1 in the 1960s, hundreds of variants have emerged, including extended-spectrum beta-lactamases (ESBLs) that confer resistance to third-generation cephalosporins. To combat this resistance, TEM beta-lactamase is targeted by inhibitors such as clavulanic acid, tazobactam, and avibactam, which are co-administered with beta-lactam antibiotics to protect them from degradation (Drawz & Bonomo, 2010). The clinical utility of these combinations is frequently challenged by the emergence of inhibitor-resistant TEM (IRT) mutations, which alter the enzyme's active site to prevent inhibitor binding while maintaining catalytic activity.

Other names

TEM-1 beta-lactamaseblaTEMClass A beta-lactamasePenicillinaseTEM β-lactamase

Beta-lactamase inhibitors act as suicide substrates or reversible inhibitors that bind to the active site of the TEM enzyme, preventing it from hydrolyzing beta-lactam antibiotics (Drawz & Bonomo, 2010).