Figure 3.

Schematic overview of shuffled DZF library construction and B2H selections to identify interacting synthetic DZFs. DZFs are represented as in Figure 1. Note that although two α-subunits are present in an RNAP complex, the DZF–DZF interaction illustrated can occur presumably because either the DZF domains on the RNAP α-fusion protein fail to dimerize (perhaps owing to a geometrical constraint) or because the RNAP complexes that are recruited to the promoter harbor one DZF domain α hybrid subunit and one wild-type α-subunit. Additional details are provided in the Results and Materials and methods section.