Effects of sigma subunit and DNA template on the accessibility of rifamycin bound to RNA polymerase

Lyle S. Rice, Claude F. Meares

Research output: Contribution to journalArticle

5 Scopus citations


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 languageEnglish (US)
Pages (from-to)51-56
Number of pages6
JournalBiochemical and Biophysical Research Communications
Issue number1
StatePublished - Mar 15 1982


ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

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