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Implication of Ile-69 and Thr-182 residues in kinetic characteristics of IRT-3 (TEM-32) beta-lactamase.

ABSTRACT: The substitution of a methionine for an isoleucine at position 69 (Met69Ile), which causes inhibitor resistance to TEM-type beta-lactamases (IRT-3 and IRT-I69), altered the positions of the Asn-170 and Glu-166 side chains as well as the position of the catalytic water molecule. A novel hydrogen bond between the hydroxyl of Thr-182 and the carbonyl of Glu-64 was expected to be responsible for the increase in the catalytic activity of the IST-T182 and IRT-3 enzymes compared with those of TEM-1 and IRT-169, respectively.

SUBMITTER: Farzaneh S

PROVIDER: S-EPMC163551 | biostudies-other | 1996 Oct

REPOSITORIES: biostudies-other

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Implication of Ile-69 and Thr-182 residues in kinetic characteristics of IRT-3 (TEM-32) beta-lactamase.

Farzaneh S S Chaibi E B EB Peduzzi J J Barthelemy M M Labia R R Blazquez J J Baquero F F

Antimicrobial agents and chemotherapy 19961001 10

The substitution of a methionine for an isoleucine at position 69 (Met69Ile), which causes inhibitor resistance to TEM-type beta-lactamases (IRT-3 and IRT-I69), altered the positions of the Asn-170 and Glu-166 side chains as well as the position of the catalytic water molecule. A novel hydrogen bond between the hydroxyl of Thr-182 and the carbonyl of Glu-64 was expected to be responsible for the increase in the catalytic activity of the IST-T182 and IRT-3 enzymes compared with those of TEM-1 and ...[more]

PMID: 8891161

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