Related Experiment Video
Updated: Aug 2, 2026
06:38
High Sensitivity Measurement of Transcription Factor-DNA Binding Affinities by Competitive Titration Using Fluorescence Microscopy
Published on: February 7, 2019
Effect of external fluctuations on the affinity-specificity negative correlation in DNA-probe interactions
1Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, India, 400005. muruga@tifr.res.in
Summary
DNA probe interactions with template DNA can be modeled as random jumps. Increasing jump size enhances probe affinity, while DNA structure and charge influence probe dynamics and target specificity.
Area of Science:
- Molecular Biology
- Biophysics
- Computational Biology
Background:
- Understanding DNA-protein or DNA-DNA interactions is crucial in molecular biology.
- The dynamics of probe DNA searching for specific sites on template DNA are complex.
- Affinity and specificity often exhibit a negative correlation, posing a challenge for molecular recognition.
Purpose of the Study:
- To model the site-specific interaction of probe DNA with template DNA as a random jump process.
- To investigate how jump size, target site fluctuations, and DNA condensation affect affinity and specificity.
- To propose strategies for simultaneously enhancing both probe affinity and specificity.
Main Methods:
- Theoretical modeling of probe DNA binding and searching dynamics on template DNA.
- Analysis of unbiased random jump processes.
- Investigation of parameters including jump size, target site position fluctuations, and target site interval fluctuations.
Main Results:
- Probe-template DNA interaction is accurately modeled as an unbiased random jump process.
- Increasing jump size enhances probe affinity up to a maximum limit.
- DNA supercoiling, condensation, and electrostatic interactions modulate probe jump dynamics.
- External fluctuations in target site position can improve affinity under high specificity conditions.
- External fluctuations in the target site interval can enhance probe specificity.
Conclusions:
- The random jump model provides a framework for understanding DNA-DNA recognition dynamics.
- Strategies involving controlled fluctuations can overcome the affinity-specificity trade-off.
- Optimized experimental conditions can be designed to simultaneously improve probe affinity and specificity.
Related Concept Videos
02:35Noncovalent Attractions in Biomolecules
Noncovalent attractions are associations within and between molecules that influence the shape and structural stability of complexes. These interactions differ from covalent bonding in that they do not involve sharing of electrons.
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
03:31Labeling DNA Probes
DNA probes are fragments of DNA labeled with a reporter tag to enable their detection or purification. The resulting labeled DNA probes can then hybridize to target nucleic acid sequences through complementary base-pairing, and may be used to recover or identify these regions.
Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...
Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...