The Flexible Ends of CENP-A Nucleosome Are Required for Mitotic Fidelity

Mol Cell. 2016 Aug 18;63(4):674-685. doi: 10.1016/j.molcel.2016.06.023. Epub 2016 Aug 4.


CENP-A is a histone variant, which replaces histone H3 at centromeres and confers unique properties to centromeric chromatin. The crystal structure of CENP-A nucleosome suggests flexible nucleosomal DNA ends, but their dynamics in solution remains elusive and their implication in centromere function is unknown. Using electron cryo-microscopy, we determined the dynamic solution properties of the CENP-A nucleosome. Our biochemical, proteomic, and genetic data reveal that higher flexibility of DNA ends impairs histone H1 binding to the CENP-A nucleosome. Substituting the 2-turn αN-helix of CENP-A with the 3-turn αN-helix of H3 results in compact particles with rigidified DNA ends, able to bind histone H1. In vivo replacement of CENP-A with H3-CENP-A hybrid nucleosomes leads to H1 recruitment, delocalization of kinetochore proteins, and significant mitotic and cytokinesis defects. Our data reveal that the evolutionarily conserved flexible ends of the CENP-A nucleosomes are essential to ensure the fidelity of the mitotic pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoantigens / genetics
  • Autoantigens / metabolism*
  • Autoantigens / ultrastructure
  • Binding Sites
  • Centromere Protein A
  • Chromosomal Proteins, Non-Histone / deficiency
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Chromosomal Proteins, Non-Histone / ultrastructure
  • Cryoelectron Microscopy
  • Cytokinesis
  • DNA / chemistry
  • DNA / metabolism*
  • Genotype
  • HeLa Cells
  • Histones / metabolism*
  • Humans
  • Kinetochores / metabolism*
  • Kinetochores / ultrastructure
  • Mice
  • Mice, Knockout
  • Mitosis / physiology*
  • Models, Molecular
  • Mutation
  • Nucleic Acid Conformation
  • Nucleosomes / metabolism*
  • Nucleosomes / ultrastructure
  • Phenotype
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Structure-Activity Relationship
  • Transfection


  • Autoantigens
  • CENPA protein, human
  • Cenpa protein, mouse
  • Centromere Protein A
  • Chromosomal Proteins, Non-Histone
  • Histones
  • Nucleosomes
  • centromere protein C
  • DNA