Recombinant bacterial RNA polymerase: Preparation and applications

Availability of DNA-dependent RNA polymerase from various bacteria is a key for setting up specific in vitro transcription systems necessary for understanding species-specific transcription regulation. We describe here two main strategies for recombinant RNA polymerase preparation—through in vitro reconstitution and heterologous co-overproduction in Escherichia coli. Both strategies can be used for preparation of large amounts of RNA polymerases from any bacteria for which sequences of rpo (RNA polymerase) genes are known.