<p>Bacterial DNA-dependent RNA polymerase (RNAP) has the core composition of alpha(2)-beta-beta'-omega, where omega is the smallest of the subunits. The omega subunit is required to promote RNAP assembly by acting like a chaperone to maintain beta' in the correct conformation and to recruit it to the alpha(2)beta subassembly to form a functional core enzyme [<cite idref="PUB00016269"/>].</p>