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Transcription factor regulation of RNA polymerase’s torque generation capacity
- Source :
- Proceedings of the National Academy of Sciences. 116:2583-2588
- Publication Year :
- 2019
- Publisher :
- Proceedings of the National Academy of Sciences, 2019.
-
Abstract
- During transcription, RNA polymerase (RNAP) supercoils DNA as it translocates. The resulting torsional stress in DNA can accumulate and, in the absence of regulatory mechanisms, becomes a barrier to RNAP elongation, causing RNAP stalling, backtracking, and transcriptional arrest. Here we investigate whether and how a transcription factor may regulate both torque-induced Escherichia coli RNAP stalling and the torque generation capacity of RNAP. Using a unique real-time angular optical trapping assay, we found that RNAP working against a resisting torque was highly prone to extensive backtracking. We then investigated transcription in the presence of GreB, a transcription factor known to rescue RNAP from the backtracked state. We found that GreB greatly suppressed RNAP backtracking and remarkably increased the torque that RNAP was able to generate by 65%, from 11.2 pN⋅nm to 18.5 pN·nm. Variance analysis of the real-time positional trajectories of RNAP after a stall revealed the kinetic parameters of backtracking and GreB rescue. These results demonstrate that backtracking is the primary mechanism by which torsional stress limits transcription and that the transcription factor GreB effectively enhances the torsional capacity of RNAP. These findings suggest a broader role for transcription factors in regulating RNAP functionality and elongation.
- Subjects :
- Multidisciplinary
Transcription, Genetic
Escherichia coli Proteins
genetic processes
DNA-Directed RNA Polymerases
Biological Sciences
Models, Theoretical
Cell biology
Kinetics
enzymes and coenzymes (carbohydrates)
chemistry.chemical_compound
chemistry
Transcription (biology)
RNA polymerase
Escherichia coli
health occupations
bacteria
DNA supercoil
Transcriptional Elongation Factors
Elongation
Transcription factor
DNA
Transcription Factors
Subjects
Details
- ISSN :
- 10916490 and 00278424
- Volume :
- 116
- Database :
- OpenAIRE
- Journal :
- Proceedings of the National Academy of Sciences
- Accession number :
- edsair.doi.dedup.....62276ab64917724f59c01c3d708613e3