FIG. 4.

Western blot analysis using specific antibodies against TP901-1 CI. (A) Protein extracts were obtained from cells expressing cI, cI3, cI6, cI11, cI14, cI15, cI20, cI41, cI75, cI98, cI101, cI113, cI120, cI121, cI122, or cI135 from the lysogenic promoter, P_R, cloned in the pCI372 plasmid. Cells containing plasmid pCI372 without a cI insert was used as a negative control. The relative amount of CI was estimated using the ImageQuant TL software. (B) Protein extracts were obtained from cells containing a functional mor gene in concert with cI, cI78, cI89, cI98, cI120, or cI135. The state of the lytic P_L promoter (open or repressed) is shown below each lane.