Figure 3.

Derivation and binding properties of a second set of σ⁷⁰ alanine substitution mutations. (A) Comparison of the residues in σ⁷⁰ and σ³² shown to be important for interaction with core polymerase. The σ³² mutant changes reconstructed as alanine substitutions in equivalent σ⁷⁰ residues are indicated in boldface. (B) Relative binding of mutant σs to core determined from the coimmunoprecipitation competition assay. Symbols and protocols as in Fig. 2C.