Lecture 7

• Regulation through modifying histone tails
  • Targets specific amino acids
    • Lysine, Arginine, Serine (less common)
  • Three methods
    • Methylation
    • Acetylation
    • Phosphorylation
  • Histone tail modification
    • Variant effects depending on method/amino acid
    • Examples
      • Acetylation of Lysine removes the polarity
        • Results in weaker nucleosome bonds and more sliding
      • Trimethylation on a H3 Lysine -> more heterochromatin
    • Reader complex
      • Histone tails attract reader complexes that recruit other proteins
    • Lysine acetylation is adding an acetyl group to the bottom (NH3^+) side of lysine
      • Removes a lot of the polarity
    • Lysine methylation is adding a lot of methyl groups where the hydrogen was on the nitrogen