SUBUNITS OF RNA-POLYMERASE IN FUNCTION AND STRUCTURE .11. IDENTIFICATION OF A SUBUNIT ASSEMBLY DOMAIN IN THE ALPHA-SUBUNIT OF ESCHERICHIA-COLI RNA-POLYMERASE

The α subunit of Escherichia coli DNA-dependent RNA polymerase is encoded by the rpoA gene and plays a major role in enzyme assembly. A set of C-terminal deletion mutations of the rpoA gene was constructed. The results of mixed reconstitution experiments in vitro, using the truncated α polypeptides encoded by the rpoA deletion mutants, suggest that the amino-terminal two-thirds of α subunit is sufficient for the formation of pseudo-core complexes containing both β and β′ subunits. © 1991.