ABCMdb

PMID: 21543331

Triboulet S, Arthur M, Mainardi JL, Veckerle C, Dubee V, Nguekam-Moumi A, Gutmann L, Rice LB, Hugonnet JE
Inactivation kinetics of a new target of beta-lactam antibiotics.
J Biol Chem. 2011 Jul 1;286(26):22777-84. Epub 2011 May 4., [PubMed]

Sentences

No. Mutations Sentence Comment

61 ABCC8 p.Ser405Asn Derivatives of pET2818 containing the same portion of the ldtfm gene with mutations leading to G430S, S405N, or both amino acid substitutions were constructed as described in the supplemental "Experimental Procedures". Login to comment 152 ABCC8 p.Ser405Asn Identification of Amino Acid Substitutions in Ldtfm-Sequencing the ldtfm gene of mutant S11 revealed two point mutations that led to amino acid substitutions S405N and G430S, both located in the catalytic domain of the LD-transpeptidase (supplemental Fig. S3). Login to comment 153 ABCC8 p.Ser405Asn Sequencing of ldtfm from the intermediary mutants showed that the two mutations appeared sequentially at the eighth (S405N) and 11th (G430S) selection steps. Login to comment 154 ABCC8 p.Ser405Asn Substitution S405N is located at the entrance of the catalytic cavity in the loop connecting sheets beta13 to beta14. Login to comment 157 ABCC8 p.Ser405Asn Kinetics of Inactivation of LD-Transpeptidases from Mutants Resistant to Imipenem-In order to analyze the impact of substitutions G430S and S405N on the catalytic constants, we constructed and purified derivatives of Ldtfm harboring these two substitutions alone or in combination. Login to comment 174 ABCC8 p.Ser405Asn The second substitution, S405N alone, caused moderate decreases in kinact (from 4.5 to 1.6 min-1 ) and k1 (from 0.065 to 0.030 ␮M -1 min-1 ). Login to comment 176 ABCC8 p.Ser405Asn Impact of amino acid substitutions S405N and G430S on the kinetics of Ldtfm inactivation by imipenem. Login to comment 223 ABCC8 p.Ser405Asn A decrease in the efficiency of enzyme acylation was expected to result in increased resistance to imipenem, and this possibility was explored by selecting mutant S11 and analyzing the impact of substitutions S405N and G430S on the kinetics of Ldtfm inactivation (Fig. 7). Login to comment