Strain AVB99 is a K12 E. coli strain (genotype: recA1 endA1 gyrA96 thi-1 hsdR17 supE44 relA1) containing pBirAcm, an engineered pACYC184 plasmid with an IPTG inducible birA gene to over-express the biotin ligase. The endA1 nuclease deficient strain is recommended for isolation of the pBirAcm plasmid that can be used to transform other E. coli strains to biotin ligase over-expressing strains. The pBirAcm plasmid should be maintained and selected with chloramphenicol at 10 μg/ml concentration. This is a low copy number plasmid. Vectors utilizing the strong tac promoter (a hybrid of the E. coli trp and lac promoters) offer protein expression levels in
excess of 10 mg/L of culture when using IPTG as a de-repressor. - See more at here.