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

Folding studies on a knotted protein.

Anna L Mallam1, Sophie E Jackson

  • 1Chemistry Department, Lensfield Road, Cambridge CB2 1EW, UK.

Journal of Molecular Biology
|February 17, 2005
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

Novel Knotted Solenoid fold with order-shifted coil arrangement leads to nontrivial 3<sub>1</sub> topology.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

Mechanism of Self-Assembly of the Gonadropin Releasing Hormone Antagonist Teverelix into Amyloid Fibrils.

Molecular pharmaceutics·2025
Same author

Observation of unique stable nano-assemblies of a lipidated glucagon-like peptide 1 analogue.

Soft matter·2025
Same author

Folding of a tandemly knotted protein: Evidence that a polypeptide chain can get out of deep kinetic traps.

Protein science : a publication of the Protein Society·2025
Same author

Effect of Lipidation on the Structure, Oligomerization, and Aggregation of Glucagon-like Peptide 1.

Bioconjugate chemistry·2025
Same author

Alternative proteoforms and proteoform-dependent assemblies in humans and plants.

Molecular systems biology·2024

The small, knotted protein YibK folds efficiently without molecular chaperones. Its reversible urea denaturation suggests a stable intermediate, challenging previous protein folding predictions.

Area of Science:

  • Protein folding
  • Structural biology
  • Biochemistry

Background:

  • Proteins can adopt complex topological structures, such as trefoil knots, which were previously thought to be impossible.
  • Knotted proteins, like YibK, are increasingly identified and present significant challenges in understanding protein folding mechanisms.
  • YibK is a small, homodimeric methyltransferase belonging to the SPOUT class, featuring a trefoil knot.

Purpose of the Study:

  • To characterize the folding and unfolding behavior of YibK, one of the smallest known knotted proteins.
  • To investigate whether YibK requires molecular chaperones for efficient folding.
  • To determine the folding pathway and thermodynamic parameters of YibK under equilibrium conditions.

Main Methods:

  • Reversible denaturation of YibK using urea in vitro.

Related Experiment Videos

  • Equilibrium unfolding experiments conducted over a wide range of protein concentrations.
  • Monitoring of secondary and tertiary structural changes using spectroscopic probes.

    • Main Results:

    • YibK can be reversibly denatured and refolded in vitro without the need for molecular chaperones.
    • Unfolding occurs via a single, protein concentration-dependent transition, consistent with a three-state equilibrium model.
    • A stable monomeric intermediate with significant secondary and tertiary structure was identified during unfolding.

    Conclusions:

    • Despite its complex trefoil knot structure, YibK folds efficiently and reversibly.
    • YibK's folding behavior is similar to non-knotted dimeric proteins under equilibrium conditions.
    • The study provides the first detailed folding analysis of a knotted protein, offering insights into the folding of these unique structures.