Figure 7.

The effect of hsdM (F269G) on the level of HsdR. The mutation hsdM (F269G) destroys only the modification activity of EcoKI. The level of HsdR was monitored by Western blots by using antibody against EcoKI. Lanes 1–6 include extracts of strains. Lanes: 1, NK301 (hsd⁺); 2, NK386 [an hsdM (F269G) derivative of NK301]; 3, an hsd⁺ derivative of NK386; 4, an hsdR(A619V) derivative of NK386 (NK388) in which alleles of hsd genes were replaced by using λhsd phages that included only hsdMS or hsdR, respectively; 5, NM802 (an hsdR deletion strain); and 6, NK352 (an hsdMS deletion strain).