Measurements of energy transfer in the rapid-diffusion limit from terbium complexes to rifamycin bound to E. coli RNA polymerase core and holoenzyme show that removal of the enzyme's sigma subunit markedly decreases the accessibility of bound rifamycin to small probe molecules in solution. Binding of holoenzyme to DNA also decreases the accessibility of enzymebound rifamycin. These results are consistent with the notion that rifamycin binds in a cleft on RNA polymerase which is held open by the sigma subunit, and which is involved in DNA binding. The use of D2O buffers to improve experimental accuracy is also described.
|Original language||English (US)|
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Mar 15 1982|
ASJC Scopus subject areas
- Molecular Biology