FIG. 3.
Expression rates of the cI-lacZ and the cIOptdb*-lacZ constructs. (A) Possible db-adb complementarity in the cI-lacZ and the cIOptdb*-lacZ mRNA, respectively. (B) E. coli strain MS59 (λwt) cells harboring plasmids pRB381-1 and pRB381-3, respectively, were grown in Luria-Bertani medium to an OD600 of 0.8. Then, triplicate samples were taken from each culture and the β-galactosidase (given in Miller units) values were determined. The two Lys codons (subsequence, 5′… AAGAAA… 3′) in λ cI wt mRNA following the putative db were omitted in the initial coding region of the cIOptdb*-lacZ construct.