J. Mukhopadhyay et al., Translocation of sigma(70) with RNA polymerase during transcription: Fluorescence resonance energy transfer assay for movement relative to DNA, CELL, 106(4), 2001, pp. 453-463
Using fluorescence resonance energy transfer, we show that, in the majority
of transcription complexes, sigma (70) is not released from RNA polymerase
upon transition from initiation to elongation, but, instead, remains assoc
iated with RNA polymerase and translocates with RNA polymerase. The results
argue against the presumption that there are necessary subunit-composition
differences, and corresponding necessary mechanistic differences, in initi
ation and elongation. The methods of this report should be generalizable to
monitor movement of any molecule relative to any nucleic acid.