Subunit assembly adaptations protein structure

Figure 5.5. A. Schematic illustration of the E. coli RNA polymerase showing the domain structure of the a subunit. The cx-NTD domain is responsible for assembly of RNAP while the a-CTD domain binds DNA and is a target for transcriptional activators. B. The two-hybrid system is based on the interaction of proteins that are fused to the X repressor and NTD domain of the a subunit of RNAP. In the example shown, Gal4 interacts with Gall IP to recruit RNAP to the promoter and activate transcription of the lacZ reporter gene. Figure adapted from Dove and Hochschild (1998).

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