When: February 8, 2017, 2:00 PM
Location: 3rd Floor Orchard View Room , Discovery Building
Contact: 608-316-4401, email@example.com
Long-lived RNA polymerase-promoter open complexes: relevance of lifetime for bacterial transcription initiation and its regulation
Transcription of DNA information into RNA by the enzyme RNA polymerase (RNAP) is the first step of gene expression. RNAP binds to a specific DNA sequence called the promoter and operates on it to form an open complex (OC) in which the DNA strands are separated in the region surrounding the transcription start site (TSS). RNAP puts the TSS base of the template strand in the catalytic active site of RNAP. This complex then binds nucleotides (NTP) and catalyzes covalent assembly of these NTP on the DNA template to make a complementary RNA chain. Rates of initiation of RNA synthesis at different promoters are highly regulated by promoter sequence, protein factors, ligands, and conditions. Rates of forming the open complex differ by about 104 for different promoters at a physiological RNAP concentration, directly affecting initiation rates. Lifetimes of promoter OC also differ by about 104, but the impact of this wide range of lifetimes on initiation was not understood. I’ll discuss some aspects of how this remarkable DNA opening and catalytic machine works, and our current understanding of how OC lifetime affects initiation of RNA synthesis in vitro and in vivo.
All qBio sponsored talks take place on Wednesdays at 2:00 p.m. in the 3rd floor Orchard View room of the Discovery Building unless otherwise noted. Talks are open to the public. Access to the room is via the elevator behind Aldo’s Cafe in the Northeast corner of the building.