Fig. 5.
To assess the relative toxicity of mutant Split T7 RNAP, we assayed the reduction in steady-state OD when T7 protein was fully induced. (A) To assess the toxicity associated with expressing mutant split T7 RNAP, we transformed plasmids containing either full-length or mutant split T7 RNAP and then assayed the OD after 10 h with or without 10 mM arabinose. (B) Of the T7 RNAP tested, gratuitous arabinose inducer does not induce a significant reduction in OD despite being able to drive large amounts of GFP expression from a PT7-regulated ORF.