Research
Research Topic
Assembly of eukaryotic ribosomes requires four ribosomal RNAs (rRNAs). The nascent ribosomal RNA precursor contains three of these rRNAs and is transcribed by the RNA polymerase (Pol) I machinery.
Using a structural biology hybrid approach and in vitro biochemistry structure-function analyses we study the molecular basis of Pol I transcription and its regulation. In combination with ex vivo and in-cell techniques, we correlate our findings with the in vivo situation.
The RNA polymerase I transcription initiation system
(DFG-funded 'Emmy Noether' project)
Cryo-EM reconstruction of the yeast RNA polymerase I early initiation intermediate including Rrn3 and Core Factor (Pilsl & Engel, Nature Communications 2020)
Combining X-ray crystallography with recent advances in cryo-electron microscopy (cryo-EM) now allows the application of an integrated structural biology hybrid approach for the analysis of transiently stable, multi-protein DNA/RNA complexes. Continuing and expanding the structural analysis of Pol I and its transcription machinery with this integrated approach allowed us to get insight into the structural basis of transcription initiation (Engel et al., Nature Communications 2016; and Engel et al., Cell 2017). We further analyzes the mechanisms of promoter recognition and DNA-duplex melting (Pilsl and Engel, Nature Communications 2020). Now, we are now interested in understanding the structural and functional basis of Pol I promoter targeting and escape in a close-to-native environment.
Mechanisms of transcription by RNA polymerase I
(SFB 960 project A8)
Cryo-EM reconstruction of the S. pombe RNA polymerase I actively elongting complex and inactive Pol I dimer (Heiss, Dai?, Becker and Engel, Nature Communications 2020)
Structural analysis of Pol I and its transcription machinery has revealed striking differences but also many similarities with Pol II and Pol III. This was demonstrated by the 3D structure of the entire 14-subunit, 590 kDa Pol I enzyme from yeast solved by X-ray crystallography (Engel et al., Nature 2013). We are now interested in studying structure-function relationships in Pol I transcription throughout organisms to understand the molecul