Dimeric association of Escherichia coli RNA polymerase alpha subunits, studied by cleavage of single-cysteine alpha subunits conjugated to iron-(S)-1-[p-(bromoacetamido)benzyl]ethylenediaminetetraacetate

A study was conducted on the proximity relationships between the two associated monomers of the Escherichia coli RNA polymerase alpha subunit using a set of four mutant alpha subunits. The findings indicate that segments of the subunit assembly domain of one subunit and the linker region between N- and C-terminal domains of the other subunit are near each other while the N-terminal regions of both subunits are very close to each other. However, intramolecular cutting was noted only within an individual N- or C-terminal domain.