"Structures and Mechanisms of RNA Polymerase Inhibition by Sigma54"
Transcription by RNA polymerase in bacteria requires specific promoter recognition by σ factors. The major variant ••••• factor (sigma54) initially forms a transcriptionally silent complex requiring specialised ATP-dependent activators that belong to AAA+ protein family for initiation. I will present our recent crystal structure of the 450 kDa RNAP-σ54 holoenzyme at 3.8 Å, which reveals molecular details of ••••••• and its interactions with RNAP. The structure explains how ••••••• targets different regions in RNAP to exert its inhibitory function. In addition, I will explain how the AAA activator uses its ATPase activity to activate RNAP-sigma54 holoenzyme. I will also compare different RNAP systems and suggest the existence of evolutionarily conserved regulatory hotspots within RNAPs that can be targeted by a diverse range of mechanisms to fine tune transcription.
Date: 10 July 2015, 11:00 (Friday, 11th week, Trinity 2015)
Venue: Wellcome Trust Centre for Human Genetics, Headington OX3 7BN
Venue Details: Meeting Rooms A & B
Speaker: Prof Xiaodong Zhang (Imperial College London )
Organising department: Division of Structural Biology
Organiser: Eleanor Martin (Wellcome Trust Centre for Human Genetics)
Organiser contact email address: jones-pa@strubi.ox.ac.uk
Hosts: Prof E.Yvonne Jones (University of Oxford), Prof David Stuart (University of Oxford)
Part of: Strubi seminars
Booking required?: Not required
Audience: Members of the University only
Editor: Eleanor Martin