Distinct Roles for Condensin's Two ATPase Sites in Chromosome Condensation

Mol Cell. 2019 Dec 5;76(5):724-737.e5. doi: 10.1016/j.molcel.2019.09.020. Epub 2019 Oct 16.

Abstract

Condensin is a conserved SMC complex that uses its ATPase machinery to structure genomes, but how it does so is largely unknown. We show that condensin's ATPase has a dual role in chromosome condensation. Mutation of one ATPase site impairs condensation, while mutating the second site results in hyperactive condensin that compacts DNA faster than wild-type, both in vivo and in vitro. Whereas one site drives loop formation, the second site is involved in the formation of more stable higher-order Z loop structures. Using hyperactive condensin I, we reveal that condensin II is not intrinsically needed for the shortening of mitotic chromosomes. Condensin II rather is required for a straight chromosomal axis and enables faithful chromosome segregation by counteracting the formation of ultrafine DNA bridges. SMC complexes with distinct roles for each ATPase site likely reflect a universal principle that enables these molecular machines to intricately control chromosome architecture.

Keywords: ABC ATPase; DNA loop extrusion; SMC complexes; chromosome condensation; cohesin; condensin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / metabolism*
  • Adenosine Triphosphatases / physiology
  • Adenosine Triphosphate / chemistry
  • Binding Sites / genetics
  • Binding Sites / physiology
  • Cell Cycle Proteins / metabolism
  • Cell Line, Tumor
  • Chromatin / physiology
  • Chromatin Assembly and Disassembly / physiology*
  • Chromosomal Proteins, Non-Histone / metabolism
  • Chromosomes / metabolism
  • Chromosomes / physiology
  • Cohesins
  • DNA / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • DNA-Binding Proteins / physiology
  • Humans
  • Multiprotein Complexes / metabolism*
  • Multiprotein Complexes / physiology
  • Protein Binding / physiology
  • Protein Subunits / metabolism

Substances

  • Cell Cycle Proteins
  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • Multiprotein Complexes
  • Protein Subunits
  • condensin complexes
  • Adenosine Triphosphate
  • DNA
  • Adenosine Triphosphatases