FIG. 4.

Competition between ς⁷⁰ and ς³² for core RNAP. The same conditions were used as described in the legend to Fig. 3, except that core RNAP was added to a mixture that contained equimolar concentrations of ς³² and ς⁷⁰ (all proteins at a final concentration of 100 nM). The sedimentation patterns of two wild-type proteins (A and B) and of the mutant proteins (C through K) are presented.