Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Helical repeat and chirality effects on DNA gel electrophoretic mobility.

J Drak1, D M Crothers

  • 1Department of Chemistry, Yale University, New Haven, CT 06511.

Proceedings of the National Academy of Sciences of the United States of America
|April 15, 1991
PubMed
Summary

Researchers determined DNA helical repeat using electrophoresis, finding 10.34 bp/turn for bent DNA. This method can measure helical repeat in any DNA segment, revealing shape-dependent migration in gels.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Climate change and the integrity of science.

Science (New York, N.Y.)·2010
Same author

RNA folding pathways.

Current protocols in nucleic acid chemistry·2008
Same author

Comparison of analyses of DNA curvature.

Journal of biomolecular structure & dynamics·2003
Same author

High-resolution transcription assay for probing drug-DNA interactions at individual drug sites.

Methods in enzymology·2001
Same author

Simultaneous measurement of binding constants and unwinding angles by gel electrophoresis.

Methods in enzymology·2001
Same author

Kinetic consequences of covalent linkage of DNA binding polyamides.

Biochemistry·2001

Area of Science:

  • Molecular Biology
  • Biophysics
  • Genetics

Background:

  • DNA structure is characterized by its helical repeat, the number of base pairs per helical turn.
  • Bent DNA sequences, such as those containing A-tracts, exhibit altered helical properties.
  • Electrophoresis is a common technique for analyzing DNA fragments, but its behavior can be influenced by DNA conformation.

Purpose of the Study:

  • To determine the precise helical repeat of bent DNA sequences.
  • To develop a novel method for evaluating the helical repeat of any DNA segment.
  • To investigate the influence of DNA superhelical chirality on electrophoretic mobility.

Main Methods:

  • Synthesized DNA multimers with varying sequence repeats (10.00-11.00 bp/turn).
  • Utilized electrophoretic mobility anomaly in polyacrylamide gels to identify maximum planar curvature.

Related Experiment Videos

  • Inserted target DNA sequences between two A-tract bends and varied phasing to calculate helical repeat.

    • Main Results:

    • Determined a helical repeat of 10.34 ± 0.04 base pairs per turn for bent DNA sequences of the A6N4-A6N5 form.
    • Established a method for calculating DNA helical repeat based on comparative electrophoresis.
    • Observed that right-handed superhelical DNA isomers migrate faster than left-handed isomers in high-percentage polyacrylamide gels.

    Conclusions:

    • The helical repeat of bent DNA is approximately 10.34 bp/turn.
    • Comparative electrophoresis offers a reliable method for assessing DNA helical repeat.
    • Superhelical chirality significantly impacts DNA migration in high-percentage polyacrylamide gels, suggesting a chiral-dependent pathway selection mechanism.