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Mapping the Structure-Function Relationships of Disordered Oncogenic Transcription Factors Using Transcriptomic Analysis
Published on: June 27, 2020
Are DNA transcription factor proteins maxwellian demons?
Longhua Hu1, Alexander Y Grosberg, Robijn Bruinsma
1Department of Physics, University of Minnesota, Minneapolis, Minnesota, USA.
Biophysical Journal
|May 6, 2008
Summary
Transcription factors (TFs) use DNA binding and sliding to find target genes. Optimized protein fluctuations minimize search time, aligning with thermodynamic limits for efficient gene regulation.
Area of Science:
- Biophysics
- Molecular Biology
- Genetics
Background:
- Transcription factors (TFs) are crucial for gene regulation, rapidly locating specific DNA sequences.
- TF search mechanisms involve 3D diffusion and 1D sliding along DNA.
- TF binding efficiency is thought to depend on conformational fluctuations between sequence-insensitive and sequence-sensitive states.
Purpose of the Study:
- To determine the shortest possible TF binding time consistent with thermodynamic principles.
- To model the role of protein conformational fluctuations in TF target site recognition.
- To investigate the thermodynamic efficiency of passive TF search mechanisms.
Main Methods:
- Developed a simplified biophysical model for TF protein conformational fluctuations.
- Analyzed the relationship between fluctuation spectrum and target site binding.
- Applied thermodynamic principles to derive theoretical binding time limits.
- Estimated binding times using parameter values relevant to bacterial TFs.
Main Results:
- The shortest binding time is achieved when the conformational fluctuation spectrum is impedance-matched to target site interactions.
- Calculated minimum binding times for bacterial TFs are close to the theoretical limit imposed by thermodynamics.
- This suggests that bacterial TFs operate near an optimized search efficiency.
Conclusions:
- Protein conformational dynamics play a key role in optimizing TF search efficiency.
- Thermodynamic constraints dictate a minimum binding time for TFs.
- Bacterial transcription factor search mechanisms appear to be finely tuned for speed and efficiency.
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