In bacteria, the sigma subunit of RNA polymerase controls promoter recognition and initiation of RNA synthesis. Using Förster energy transfer between single molecules (smFRET), we have demonstrated that Mycobacterium tuberculosis, the causative agent of tuberculosis, uses a yet unknown transcriptional activation mechanism in which the RNA polymerase retains the sigma subunit in inactive « closed » conformation unless it is stabilized in the "open" active conformation by the activator protein RbpA.
This collaborative work between the groups of Emmanuel Margeat (CBS) and Konstantin Brodolin (IRIM, Montpellier) was published on May 23, 2018 in Science Advances