A group of enzymes of varying specificity hydrolysing beta-lactams; some act more rapidly on penicillins, some more rapidly on cephalosporins. The latter were formerly listed as EC 220.127.116.11, cephalosporinase.
; different in molecular weight, localization, metal ion requirement; different in molecular weight, localization, metal ion requirement; different in molecular weight, localization, metal ion requirement
the recombinant plasmid pVT-1 is used as a source of the blaOXA-48 gene. The blaOXA-48 ORF is subcloned into expression vector pET-9a to yield recombinant plasmid pET-OXA-48. Escherichia coli MCT236(DE3) is used as the host for overproduction of the OXA-48 enzyme
the chloramphenicol acetyltransferase gene replaces the blaTEM-1 gene as the selectable marker, allowing plasmid maintenance using 0.0125 mg/ml chloramphenicol. The blaTEM-1 gene is then subcloned under control of the IPTG-inducible promoter and mutated. The resulting constructs harbor a 6-histidine tag that is N-terminal to the native TEM-1 signal peptide. Upon processing of the signal peptide during expression and maturation in Escherichia coli, the histidine tag is also removed
MSC15369, IMP-1 is PCR amplified from plasmid DNA prepared from a carbapenems-resistant Pseudomonas aeruginosa MSC15369. The PCR product is cloned into pTrcHis2 TOPO vector (Invitrogen, Carlsbad, CA) and expressed in Escherichia coli DH5a after induction with 0.5 mM isopropyl-beta-D-(-)-thiogalactopyranoside for 3 h at room temperature
using the template blaSHV-1 gene in the phagemid vector pBC SK(-), degeneration of oligonucleotides at Ambler position 276 to make the full complement of amino acid substitutions. After PCR mutagenesis, electroporation of the resultant plasmids into Escherichia coli
strain IP97; strain IP97. In the bla gene from strain IP97 a deletion of 51 bp results in a completely inactive beta-lactamase. In the ampC gene from strain Y56 the A751G mutation is responsible for the inactivation of beta-lactamase