Human Condensin I and II Drive Extensive ATP-Dependent Compaction of Nucleosome-Bound DNA

Mol Cell. 2020 Jul 2;79(1):99-114.e9. doi: 10.1016/j.molcel.2020.04.026. Epub 2020 May 22.

Abstract

Structural maintenance of chromosomes (SMC) complexes are essential for genome organization from bacteria to humans, but their mechanisms of action remain poorly understood. Here, we characterize human SMC complexes condensin I and II and unveil the architecture of the human condensin II complex, revealing two putative DNA-entrapment sites. Using single-molecule imaging, we demonstrate that both condensin I and II exhibit ATP-dependent motor activity and promote extensive and reversible compaction of double-stranded DNA. Nucleosomes are incorporated into DNA loops during compaction without being displaced from the DNA, indicating that condensin complexes can readily act upon nucleosome-bound DNA molecules. These observations shed light on critical processes involved in genome organization in human cells.

Keywords: DNA curtain; SMC complexes; chromosome organization; condensin; crosslinking mass spectroscopy; electron microscopy; loop extrusion; single molecule.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / chemistry*
  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / metabolism*
  • Adenosine Triphosphate / metabolism*
  • DNA / chemistry*
  • DNA / metabolism*
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Humans
  • Models, Molecular
  • Multiprotein Complexes / chemistry*
  • Multiprotein Complexes / genetics
  • Multiprotein Complexes / metabolism*
  • Nucleosomes / metabolism*
  • Protein Binding
  • Protein Conformation
  • Single Molecule Imaging / methods

Substances

  • DNA-Binding Proteins
  • Multiprotein Complexes
  • Nucleosomes
  • condensin complexes
  • Adenosine Triphosphate
  • DNA
  • Adenosine Triphosphatases