Related Experiment Video
Updated: Jun 12, 2026
08:48
Targeted in Situ Mutagenesis of Histone Genes in Budding Yeast
Published on: January 26, 2017
Functional evolution of bacterial histone-like HU proteins
1Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA. agrove@lsu.edu
Current Issues in Molecular Biology
|May 21, 2010
Summary
Bacterial histone-like HU proteins shape DNA structure for essential cellular processes. Their distinct binding properties allow for specialized roles in DNA replication, repair, and gene regulation.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Bacterial histone-like HU proteins are essential for nucleoid structure and DNA-dependent processes like replication and gene regulation.
- While conserved, HU protein homologs display diverse DNA binding specificities and affinities, suggesting functional divergence.
Purpose of the Study:
- To investigate the molecular mechanisms underlying the distinct DNA binding specificities of bacterial HU protein homologs.
- To elucidate how these proteins induce specific DNA topologies and contribute to higher-order nucleoprotein structures.
Main Methods:
- Analysis of DNA-protein interactions.
- Characterization of DNA structural deformations induced by HU proteins.
- Comparative analysis of HU protein homologs with varying DNA binding properties.
Main Results:
- HU proteins select DNA targets based on intrinsic DNA flexure, stabilized kinks, and salt-bridge interactions.
- Specific HU homologs induce distinct DNA structural deformations, explaining their varied binding properties.
- Some HU homologs possess an additional lysine-rich domain, similar to eukaryotic histone H1, indicating further evolutionary divergence.
Conclusions:
- The distinct binding properties of HU homologs arise from specific interactions with DNA structure, enabling specialized in vivo functions.
- HU proteins' ability to modulate DNA topology is crucial for their architectural and regulatory roles.
- Evolutionary divergence in HU proteins, including the presence of histone H1-like domains, expands their functional repertoire in bacteria.
Related Concept Videos
02:30Histone Variants at the Centromere
Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3 variants are also...
02:32Histone 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,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:32Histone 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,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
01:12The 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...
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...
02:10The 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.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
01:24Nucleoid
The nucleoid represents a structurally and functionally distinct region within prokaryotic cells, where the cell's DNA and associated proteins are housed. Unlike eukaryotic cells, prokaryotes lack a membrane-bound nucleus, and the nucleoid facilitates the organization and accessibility of the genetic material within this constraint. The DNA in most bacteria and archaea exists as a single, circular, double-stranded molecule that is highly compacted through supercoiling and interactions with...