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 Concept Videos

Heterochromatin02:38

Heterochromatin

The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Mismatch Repair01:20

Mismatch Repair

Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
Molecular Chaperones and Protein Folding03:00

Molecular Chaperones and Protein Folding

The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
Euchromatin01:01

Euchromatin

The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions take up more dye, appearing darker, while the less-compact areas take up less dye and appear lighter. Based on the compaction level, chromatins are classified into two primary forms – euchromatin and heterochromatin.
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
Histone Modification02:32

Histone Modification

The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...

You might also read

Related Articles

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

Sort by
Same author

Artificial repression looping control by regulated autoinhibition of transcription activator-like effector dimer proteins.

Nucleic acids research·2026
Same author

Iron-addicted colorectal cancers exploit heme-complex II axis to resist oxidative cell death.

Cell metabolism·2026
Same author

Unbiased CRISPR synthetic lethal screening for genetic vulnerabilities in a succinate dehydrogenase-loss model of paraganglioma.

iScience·2026
Same author

Cell-SELEX identifies a DNA aptamer for highly selective in vivo siRNA delivery in cholangiocarcinoma.

JHEP reports : innovation in hepatology·2026
Same author

<i>In Vivo</i> Selection of anti-glioblastoma DNA aptamer-drug conjugates in an orthotopic patient-derived xenograft model.

bioRxiv : the preprint server for biology·2026
Same author

Iron addicted colorectal cancers exploit Heme-Complex II axis to resist oxidative cell death.

bioRxiv : the preprint server for biology·2025

Related Experiment Video

Updated: Jul 4, 2026

Escherichia coli -Based Complementation Assay to Study the Chaperone Function of Heat Shock Protein 70
07:14

Escherichia coli -Based Complementation Assay to Study the Chaperone Function of Heat Shock Protein 70

Published on: March 8, 2024

Eukaryotic HMGB proteins as replacements for HU in E. coli repression loop formation.

Nicole A Becker1, Jason D Kahn, L James Maher

  • 1Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First St. SW, Rochester, MN 55905, USA.

Nucleic Acids Research
|June 3, 2008
PubMed
Summary

Yeast HMGB proteins can rescue DNA looping defects in bacteria lacking essential HU proteins. These proteins enhance DNA looping more effectively than native HU, suggesting they alter DNA twist in vivo.

More Related Videos

Site Specific Lysine Acetylation of Histones for Nucleosome Reconstitution using Genetic Code Expansion in Escherichia coli
07:26

Site Specific Lysine Acetylation of Histones for Nucleosome Reconstitution using Genetic Code Expansion in Escherichia coli

Published on: December 26, 2020

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo
08:32

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo

Published on: October 23, 2016

Related Experiment Videos

Last Updated: Jul 4, 2026

Escherichia coli -Based Complementation Assay to Study the Chaperone Function of Heat Shock Protein 70
07:14

Escherichia coli -Based Complementation Assay to Study the Chaperone Function of Heat Shock Protein 70

Published on: March 8, 2024

Site Specific Lysine Acetylation of Histones for Nucleosome Reconstitution using Genetic Code Expansion in Escherichia coli
07:26

Site Specific Lysine Acetylation of Histones for Nucleosome Reconstitution using Genetic Code Expansion in Escherichia coli

Published on: December 26, 2020

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo
08:32

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo

Published on: October 23, 2016

Area of Science:

  • Molecular Biology
  • Genetics
  • Biochemistry

Background:

  • DNA looping is crucial for gene regulation and recombination in both prokaryotes and eukaryotes.
  • Sequence-nonspecific DNA-binding proteins, such as bacterial heat unstable (HU) and eukaryotic high-mobility group B (HMGB) proteins, modulate DNA flexibility by inducing bends or kinks.
  • These architectural proteins play vital roles in altering DNA structure for various cellular processes.

Purpose of the Study:

  • To investigate the ability of eukaryotic high-mobility group B (HMGB) proteins and their derivatives to functionally complement a DNA looping defect in Escherichia coli lacking HU protein.
  • To explore whether yeast HMGB proteins can substitute for bacterial HU protein in DNA looping.
  • To determine if human HMGB2-box A derivatives can rescue the observed DNA looping defect.

Main Methods:

  • Utilized a sensitive genetic assay for DNA looping in living Escherichia coli cells.
  • Assessed the ability of yeast HMGB protein derivatives (Nhp6A) to rescue DNA looping in E. coli strains deficient in HU protein.
  • Evaluated the effect of human HMGB2-box A derivatives on DNA looping in the same E. coli system.
  • Analyzed DNA length-dependence of repression efficiency to infer changes in DNA structure.

Main Results:

  • Derivatives of the yeast HMGB protein Nhp6A successfully rescued DNA looping in E. coli lacking HU protein.
  • In some cases, Nhp6A facilitated DNA looping more efficiently than the native HU protein.
  • Nhp6A induced changes in the DNA length-dependence of repression, suggesting an alteration of DNA twist in vivo.
  • Human HMGB2-box A derivatives did not demonstrate a rescue effect on DNA looping.

Conclusions:

  • Yeast HMGB proteins, specifically Nhp6A derivatives, can functionally substitute for bacterial HU protein in DNA looping.
  • Nhp6A exhibits potent DNA looping activity in vivo, potentially exceeding that of native HU.
  • Nhp6A appears to modulate DNA structure by altering DNA twist, impacting gene regulation mechanisms.
  • Structural differences between yeast and human HMGB proteins may explain their differential functional complementation capabilities in this bacterial system.