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Updated: Jul 2, 2025
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Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events
Published on: May 13, 2019
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Distinct negative elongation factor conformations regulate RNA polymerase II promoter-proximal pausing
Bonnie G Su1, Seychelle M Vos2
1Department of Biology, Massachusetts Institute of Technology, Building 68, 31 Ames St., Cambridge, MA 02139, USA.
Molecular Cell
|February 24, 2024
Summary
The study reveals how the Negative Elongation Factor (NELF) complex adopts distinct conformations to regulate RNA polymerase II (Pol II) pausing and elongation during gene expression. NELF
Area of Science:
- Molecular Biology
- Gene Regulation
- Structural Biology
Background:
- Metazoan gene expression relies on RNA polymerase II (Pol II) pausing.
- DSIF and NELF are key factors stabilizing Pol II pausing.
- NELF's role in elongation versus pausing has been debated.
Purpose of the Study:
- To elucidate the structural mechanisms of NELF in regulating Pol II transcription.
- To understand how NELF transitions between paused and poised states.
- To define NELF's role in Pol II reactivation and elongation.
Main Methods:
- Cryoelectron microscopy (cryo-EM) to determine structures of Pol II-DSIF-NELF complexes.
- Biochemical assays to assess NELF conformations and interactions.
- Analysis of NELF-A tentacle interactions with RPB2.
Main Results:
- Identified two NELF conformations: paused and poised.
- The paused state promotes Pol II stalling, while the poised state allows elongation.
- The poised NELF state facilitates TFIIS binding for Pol II reactivation.
- NELF-A's interaction with RPB2 is crucial for Pol II pausing.
Conclusions:
- NELF dynamically regulates Pol II activity through distinct structural states.
- NELF facilitates both transcription pausing and subsequent reactivation/elongation.
- Structural insights into NELF function provide a framework for understanding gene expression control.
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