Publications by authors named "Iris Thamm"
Article Synopsis
- - The B3 FEZ-1 beta-lactamase enzyme from Fluoribacter (Legionella) gormanii breaks down various antibiotics, including penicillins and carbapenems, and is dependent on zinc for its activity.
- - Researchers created five specific mutants of FEZ-1 to study how changes to certain amino acids affect zinc and substrate binding, revealing important insights into the enzyme's functionality.
- - The study found that some mutants altered the enzyme's effectiveness against certain antibiotics, with one mutant forming an inactive complex with hydrolyzed cephalosporins.
In the absence of penicillin, the beta-lactamase encoding gene blaP of Bacillus licheniformis 749/I is negatively regulated by the transcriptional repressor BlaI. Three palindromic operator regions are recognized by BlaI: two in the blaP promoter (OP1 and OP2) and one (OP3) in the promoter of the blaI-blaR1 operon. In this study, the dissociation constant of the purified BlaI dimer was estimated at 25 microm by equilibrium ultracentrifugation.
View Article and Find Full Text PDFA penicillin-resistant mutant, JH2-2r (MIC 75 microg ml(-1)), was isolated from Enterococcus faecalis JH2-2 (MIC 5 microg ml(-1)) by successive passages on plates containing increasing concentrations of benzylpenicillin. A comparison of the penicillin-binding protein (PBP) profiles in the two strains revealed a more intensely labelled PBP4 in JH2-2r. Because the sequences of the JH2-2 and JH2-2r pbp4 genes were strictly identical, even in their promoter regions, this intensive labelling could only be associated with an overproduction of the low-affinity PBP4.
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