Figure 4.

Complex formation in the absence of a heparin challenge. (A) Gel image. RNAP with different amino acids residues at positions 430 and 433 in σ⁷⁰, and either Duplex or −11 2AP Duplex DNA were incubated at room temperature. After complex formation the samples were loaded onto a non-denaturing polyacrylamide gel without prior challenge with heparin. (B) Quantification of the results. Work-up of samples was as indicated in Materials and Methods and the legend to Figure 2.