Related Experiment Video

Updated: Mar 29, 2026

Methodology for Accurate Detection of Mitochondrial DNA Methylation
12:11

Methodology for Accurate Detection of Mitochondrial DNA Methylation

Published on: May 20, 2018

14.0K

Yeast mitochondrial HMG proteins: DNA-binding properties of the most evolutionarily divergent component of

Jana Bakkaiova1, Victoria Marini2, Smaranda Willcox3

  • 1Departments of Genetics and Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynska dolina, Ilkovicova 6, 842 15 Bratislava, Slovak Republic.

Bioscience Reports
|December 10, 2015
PubMed

Insights

Yeast mitochondrial high-mobility group (HMG)-box containing (mtHMG) proteins bind weakly to dsDNA but prefer DNA recombination intermediates. This suggests their role in mitochondrial DNA maintenance involves these structures.

Area of Science:

  • Mitochondrial genetics
  • Molecular biology
  • Yeast genetics

Background:

  • Yeast mitochondrial DNA (mtDNA) is organized into nucleoprotein structures known as mitochondrial nucleoids (mt-nucleoids).
  • Mitochondrial high-mobility group (HMG)-box containing (mtHMG) proteins are key mediators of mt-nucleoid formation.
  • mtHMG proteins are among the fastest evolving components of mt-nucleoids, but their biochemical properties remain largely unexplored.

Purpose of the Study:

  • To investigate whether the amino acid sequence divergence of yeast mtHMG proteins is associated with diversification in their biochemical properties.
  • To compare the DNA-binding characteristics of mtHMG proteins from different yeast species.

Main Methods:

  • Comparative biochemical analysis of mtHMG proteins from Saccharomyces cerevisiae (ScAbf2p), Yarrowia lipolytica (YlMhb1p), and Candida parapsilosis (CpGcf1p).
  • Assessment of protein binding affinities to intact double-stranded DNA (dsDNA), Holliday junctions (HJ), and replication forks (RF).

Main Results:

  • All three analyzed mtHMG proteins exhibited weak binding to intact dsDNA.
  • ScAbf2p and YlMhb1p showed quantitative binding to dsDNA only at very high protein concentrations.
  • CpGcf1p demonstrated negligible binding to dsDNA.
  • In contrast, all three proteins displayed significantly higher preference for binding to DNA recombination intermediates like HJ and RF.

Conclusions:

  • Yeast mtHMG proteins likely play a crucial role in mtDNA maintenance and compaction in vivo through their preferential binding to recombination and replication intermediates.
  • The distinct biochemical properties of CpGcf1p may contribute to the evolutionary flexibility observed in the mitochondrial genome structure within the CTG-clade yeast species.
Keywords:
DNA compactionDNA-binding proteinHMG-box containing proteinHolliday junctionmitochondrial DNA (mtDNA)mitochondrial nucleoid

More Related Videos

Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy11:40

Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy

Published on: June 25, 2013

12.5K
Labelling and Visualization of Mitochondrial Genome Expression Products in Baker's Yeast Saccharomyces cerevisiae08:33

Labelling and Visualization of Mitochondrial Genome Expression Products in Baker's Yeast Saccharomyces cerevisiae

Published on: April 11, 2021

5.0K

Related Concept Videos

Eukaryotic Transcription Inhibitors01:52

Eukaryotic Transcription Inhibitors

Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a...
11.3K
Animal Mitochondrial Genetics02:59

Animal Mitochondrial Genetics

Among all the organelles in an animal cell, only mitochondria have their own independent genomes. Animal mitochondrial DNA is a double-stranded, closed-circular molecule with around 20,000 base pairs. Mitochondrial DNA is unique in that one of its two strands, the heavy, or H, -strand is guanine rich, whereas the complementary strand is cytosine rich and called the light, or L, -strand. Compared to nuclear DNA, mitochondrial DNA has a very low percentage of non-coding regions and is marked by...
10.0K
The Nucleosome Core Particle01:12

The Nucleosome Core Particle

Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
2.7K
Conserved Binding Sites01:49

Conserved Binding Sites

Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function.
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally...
5.3K
Mitochondrial Precursor Proteins01:39

Mitochondrial Precursor Proteins

Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70  chaperones are targetted to TOM20-TOM22 receptor complexes.
Most of the mitochondrial...
3.9K
Yeast Signaling01:28

Yeast Signaling

Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
18.5K