Histones and their assembly

Small (10 – 13kD), basic and highly conserved. Form a solenoid (supercoiled) structure with DNA wound around core of histone protein. Nucleosome contains twomolecules of H2A, H2B, H3 and H4, plus one of H1. Assembly: The “handshake” interaction between H3-H4 tetramer and 2x H2A-H2B dimers. Histones are modified at their “tails”: Acetylated, Methylated, Phosphorylated or Ubiquitylated.