3D structure: histones, chromatin and chromosome

  • Chromosomes contain all the DNAs in the cell nucleus. Fully stretched DNA is about 2 meters long. The double helix structure has to be tightly packaged in the nucleus.
  • The double helix wraps around histones and form a “beads on string” structure, The histones pack together into chromatin fiber, that eventually lead to chromosomes.

Image from National Human Genome Research Institute

Source: https://www.genome.gov/genetics-glossary/Chromatin