Description
This strain contains the T7 RNA polymerase gene as well as the plasmid pLysE that constitutively expresses T7 lysozyme, a natural inhibitor of T7 RNA Polymerase. This strain is used to minimize basal level expression of potentially toxic gene products before induction with IPTG. When induced with IPTG, the stronger T7 promoter overcomes the inhibition of T7 RNA polymerase expression by T7 lysozyme. The pLysE plasmid provides the highest level of repression of the T7 RNA Polymerase gene prior to induction. Transformation efficiency >1 X 107 cfu/μg of pUC19