Antibodies against the subunits of E. coli RNA polymerase as probes for subunit-specific binding of DNA and other ligands.

Antibodies against the isolated subunits alpha, beta, and beta' of DNA-dependent RNA polymerase from E. coli have been prepared. They have been used to compare the extent of antibody-binding, as measured by complement fixation, to the isolated subunits and to the intact enzyme, in the absence and presence of ligands, such as inhibitors, nucleotides, nucleosides, oligo- and poly-nucleotides, and DNA of different composition. In many cases the results show a subunit-specific dependence of complement fixation upon the presence of a ligand and suggest a functional topography of the interaction between the subunits alpha, beta, and beta' of RNA polymerase and defined nucleotide sequences and small ligands.