How is compaction modulated?

When DNA wraps around nucleosome core particles, histone tails stick out beyond the DNA
This effects how nucleosomes interact with eachother (compaction) and other proteins eg TFs
Histone tails are accessible to enzymes and can be chemically modified which change the properties of histone tails eg charge
- Allows for much variation and potential for complex information (epigenetic)= histone code
- Each cell type will have a different variation of its own histone code
- Common modifications: Acetylation, phosphorylation, methylation, ubiquitination
- Modifications usually occur to amino acids: arginine, lysine, serine
  - Eg H3K27Me3- three methyl groups(M) to lysine (K) at amino acid position 27 in histone H3
    - Reversible, pushes chromatin towards heterochromatin state, supressive

	Creado por Chloe Cavarretta hace más de 7 años

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3. Chromatin and Nuclear Structure