Cooperative stabilization of Mycobacterium tuberculosis rrnAP3 promoter open complexes by RbpA and CarD.

ABSTRACT: The essential mycobacterial transcriptional regulators RbpA and CarD act to modulate transcription by associating to the initiation complex and increasing the flux of transcript production. Each of these factors interacts directly with the promoter DNA template and with RNA polymerase (RNAP) holoenzyme. We recently reported on the energetics of CarD-mediated open complex stabilization on the Mycobacterium tuberculosis rrnAP3 ribosomal promoter using a stopped-flow fluorescence assay. Here, we apply this approach to RbpA and show that RbpA stabilizes RNAP-promoter open complexes (RPo) via a distinct mechanism from that of CarD. Furthermore, concentration-dependent stopped-flow experiments with both factors reveal positive linkage (cooperativity) between RbpA and CarD with regard to their ab

SUBMITTER: Rammohan J 

PROVIDER: S-EPMC5009747 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature