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Updated: May 21, 2026
07:26
Site Specific Lysine Acetylation of Histones for Nucleosome Reconstitution using Genetic Code Expansion in Escherichia coli
Published on: December 26, 2020
A facile method to synthesize histones with posttranslational modification mimics.
Zhiyong U Wang1, Yane-Shih Wang, Pei-Jing Pai
1Department of Chemistry, Texas A&M University, College Station, TX 77843, USA.
Biochemistry
|June 16, 2012
Summary
Researchers genetically incorporated Se-alkylselenocysteine into histone H3, creating a novel method for synthesizing post-translationally modified histone mimics. This technique enables the study of histone modifications and their biological functions.
Area of Science:
- Biochemistry
- Molecular Biology
- Chemical Biology
Background:
- Histone post-translational modifications (PTMs) are crucial for regulating gene expression and chromatin structure.
- Existing methods for synthesizing PTMs often face challenges in yield and specificity.
- Developing efficient methods to create modified histones is essential for studying their biological roles.
Purpose of the Study:
- To develop a novel genetic method for incorporating non-natural amino acids into histone H3.
- To utilize this method for creating biologically active histone H3 mimics with specific PTMs.
- To enable further investigation into the functional consequences of histone modifications.
Main Methods:
- Engineered pyrrolysyl-tRNA synthetase-tRNA(Pyl) pair for genetic code expansion.
- Site-specific incorporation of Se-alkylselenocysteine into histone H3.
- Oxidative elimination of selenocysteine followed by thiol-ene click chemistry.
- Synthesis of histone H3 mimics with lysine methylation, lysine acetylation, and serine phosphorylation.
Main Results:
- Achieved high protein expression yield of histone H3 with incorporated Se-alkylselenocysteine.
- Successfully generated biologically active H3 mimics with defined PTMs.
- Demonstrated the versatility of the method for introducing multiple types of modifications.
Conclusions:
- The developed genetic incorporation and chemical modification strategy provides a powerful tool for synthesizing histone PTM mimics.
- This approach facilitates the study of histone function and epigenetic regulation.
- Offers a new avenue for creating customized histone variants for biochemical and structural studies.
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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
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01:32Chromatin Modification in iPS Cells
Chromatin modification alters gene expression; therefore, scientists can add histone-modifying enzymes, histone variants, and chromatin remodeling complexes to somatic cells to aid reprogramming into pluripotent stem (iPS) cells.
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
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The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex.
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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.
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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.
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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...
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