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

How Chi Sequence Modifies RecBCD Single-Stranded DNA Translocase Activity.

Chia-Chuan Cho1, Cinya Chung1, Hung-Wen Li1

  • 1Department of Chemistry, National (Taiwan) University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan.

Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry
|October 17, 2017
PubMed
Summary
This summary is machine-generated.

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

Improving the efficacy of anti-SSEA4 antibody in pancreatic cancer immunotherapy with glyco-optimization and immune checkpoint blockade.

Proceedings of the National Academy of Sciences of the United States of America·2025
Same author

SWI5-SFR1 reduces RAD51 recombinase extending units during filament assembly.

Nucleic acids research·2025
Same author

Chemical and Enzymatic Synthesis of DisialylGb5 and Other Sialosides for Glycan Array Assembly and Evaluation of Siglec-Mediated Immune Checkpoint Inhibition.

Molecules (Basel, Switzerland)·2025
Same author

Expression of Human β3GalT5-1 in Insect Cells as Active Glycoforms for the Efficient Synthesis of Cancer-Associated Globo-Series Glycans.

Journal of the American Chemical Society·2025
Same author

Mug20-Rec25-Rec27 binds DNA and enhances meiotic DNA break formation via phase-separated condensates.

Nucleic acids research·2025
Same author

Hop2-Mnd1 functions as a DNA sequence fidelity switch in Dmc1-mediated DNA recombination.

Nature communications·2024

The RecBCD enzyme

Area of Science:

  • Molecular biology
  • DNA repair mechanisms
  • Enzymology

Background:

  • The RecBCD enzyme complex in E. coli plays a dual role in DNA metabolism, initiating homologous repair and degrading foreign DNA.
  • Recognition of the chi sequence (5'-GCTGGTGG-3') is critical for switching RecBCD from a degradative to a repair-promoting state, facilitating RecA-mediated recombination.
  • RecBCD comprises multiple translocase activities: a 3'-to-5' ssDNA translocase in RecB, a 5'-to-3' translocase in RecD, and a secondary activity associated with RecBC.

Purpose of the Study:

  • To elucidate how the chi sequence specifically modulates the distinct translocase activities within the E. coli RecBCD complex.
  • To investigate the functional roles and interactions of the RecB, RecC, and RecD subunits during DNA translocation and chi recognition.
  • To understand the mechanism by which RecBCD transitions from DNA degradation to promoting recombination.
Keywords:
Brownian motionDNARecBCDchi recognitionssDNA translocase

Related Experiment Videos

Main Methods:

  • Direct visualization of individual RecBCD complexes translocating along DNA substrates containing single-stranded DNA (ssDNA) gaps.
  • Utilizing DNA substrates with ssDNA gaps of varying polarities (3'-to-5' and 5'-to-3') to assess translocase activity.
  • Employing wild-type and RecD-defective (RecBCD^K177Q) RecBCD mutants to differentiate translocase functions.

Main Results:

  • The 3'-to-5' translocase activity of RecB is unaffected by the chi sequence and exhibits low processivity.
  • Chi recognition leads to a significant increase in RecBCD dissociation from 5'-to-3' ssDNA, indicating inactivation of the RecD 5'-to-3' translocase.
  • A RecD-defective mutant revealed a chi-independent secondary translocase activity associated with RecBC, crucial for processive DNA unwinding.

Conclusions:

  • The RecBCD complex possesses multiple, differentially regulated ssDNA translocases that are essential for its functions in DNA repair and recombination.
  • Chi sequence recognition specifically inactivates the RecD-mediated 5'-to-3' translocase activity, while the RecB 3'-to-5' activity remains functional but less processive.
  • The interplay between these translocases, particularly the chi-independent RecBC activity, ensures efficient and processive unwinding of DNA substrates for recombination.