FIGURE 6.

Stability of LacY and lack of promoter read-through. Cells were uniformly labeled with ³⁵S as described under “Experimental Procedures” in the presence of aTc and IPTG (lane 1). After removing IPTG, aTc, and radiolabel, cells were grown for 3.5 h (lane 2). Cells were also grown without first in the presence of IPTG and aTc but without radiolabel and then for 3.5 h without inducers but in the presence of radiolabel (lane 3). Equal aliquots of the cell culture were subjected to immunoprecipitation with pAb and SDS-PAGE. The radiolabeled LacY bands in lanes 2 and 3 were quantified relative to lane 1 as described under “Experimental Procedures.”