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

Slow assembly and disassembly of lambda Cro repressor dimers.

Haifeng Jia1, W John Satumba, Gene L Bidwell

  • 1Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677, USA.

Journal of Molecular Biology
|June 29, 2005
PubMed
Summary

Cro protein dimer assembly is slow under native conditions, suggesting kinetic control of its in vivo DNA binding and impacting bacteriophage lambda

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

Proof-of-principle of Distributed Acoustic Sensing (DAS) for detection of sewer defects, extraneous water intrusion and sewage exfiltration.

Water science and technology : a journal of the International Association on Water Pollution Research·2026
Same author

Genetic architecture of sugarcane traits in a polyploid genomics framework.

Nature·2026
Same author

Bioinspired Hierarchically Porous Polyimide Films with Moisture-Resistant Low-κ Dielectric Performance.

ACS applied materials & interfaces·2026
Same author

Upgrading of Gray and Green Infrastructure optimized combination: Synergistic decision tools under resilience demand and investment constraints.

Environmental research·2026
Same author

A haplotype-resolved genome assembly of seed hemp (<i>Cannabis sativa</i>) and analysis of Y chromosome divergence from the X.

Horticulture research·2026
Same author

Optimizing delivery of an anti-cytomegalovirus inhibitory peptide using a cell-penetrating peptide.

The Journal of general virology·2026

Area of Science:

  • Molecular Biology
  • Biophysics
  • Protein Dynamics

Background:

  • Cro protein dimers are essential for repressing transcription via operator DNA binding.
  • Dimerization of Cro is relatively weak compared to its DNA binding affinity.
  • Understanding Cro dimer assembly kinetics is crucial for deciphering its regulatory role.

Purpose of the Study:

  • To investigate the equilibria and kinetics of Cro dimer assembly using fluorophore-conjugated variants.
  • To determine the rate constants for Cro dimer dissociation and association.
  • To explore the influence of DNA and protein structure on dimer formation.

Main Methods:

  • Utilized single-cysteine variants of Cro conjugated with fluorophores.
  • Employed fluorescence resonance energy transfer (FRET) to monitor equilibrium distributions of mixed dimers.

Related Experiment Videos

  • Performed subunit exchange experiments to measure dimer dissociation and association rate constants.

    • Main Results:

    • Equilibrium dissociation constants for labeled Cro variants are in the micromolar range.
    • First-order rate constants for dimer dissociation range from 0.02 s⁻¹ to 0.04 s⁻¹.
    • Association rate constants vary from 0.7x10⁴ M⁻¹s⁻¹ to 3x10⁴ M⁻¹s⁻¹; DNA-driven assembly shows slightly enhanced rates (7x10⁴ to 9x10⁴ M⁻¹s⁻¹).
    • Native Cro dimer assembly is over four orders of magnitude slower than previously observed refolding rates and is unaffected by peptidyl-prolyl isomerases.
    • Stabilizing Cro's folded structure (e.g., F58W variant, low temperature) reduces subunit exchange.
    • Native monomers appear compact with high unfolding barriers; assembly favors unfolded/partially folded monomers.

    Conclusions:

    • Cro dimer assembly is a slow process under native conditions, contrasting with rapid refolding observations.
    • The data suggest that Cro binding in vivo may be under kinetic rather than thermodynamic control.
    • The slow dimer assembly kinetics offer a new perspective on the bacteriophage lambda lysis-lysogeny switch.