Condensin- and Replication-Mediated Bacterial Chromosome Folding and Origin Condensation Revealed by Hi-C and Super-resolution Imaging

Mol Cell. 2015 Aug 20;59(4):588-602. doi: 10.1016/j.molcel.2015.07.020.


Chromosomes of a broad range of species, from bacteria to mammals, are structured by large topological domains whose precise functional roles and regulatory mechanisms remain elusive. Here, we combine super-resolution microscopies and chromosome-capture technologies to unravel the higher-order organization of the Bacillus subtilis chromosome and its dynamic rearrangements during the cell cycle. We decipher the fine 3D architecture of the origin domain, revealing folding motifs regulated by condensin-like complexes. This organization, along with global folding throughout the genome, is present before replication, disrupted by active DNA replication, and re-established thereafter. Single-cell analysis revealed a strict correspondence between sub-cellular localization of origin domains and their condensation state. Our results suggest that the precise 3D folding pattern of the origin domain plays a role in the regulation of replication initiation, chromosome organization, and DNA segregation.

Keywords: DNA replication; bacterial mitosis; chromosome conformation capture; chromosome segregation; chromosome structure and organization; condensins; super-resolution microscopy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / metabolism*
  • Bacillus subtilis / genetics*
  • Bacillus subtilis / metabolism
  • Bacillus subtilis / ultrastructure
  • Bacterial Proteins / metabolism*
  • Chromosomes, Bacterial / ultrastructure
  • DNA Replication
  • DNA, Superhelical
  • DNA-Binding Proteins / metabolism*
  • Microscopy
  • Models, Molecular
  • Multiprotein Complexes / metabolism*
  • Optical Imaging
  • Replication Origin


  • Bacterial Proteins
  • DNA, Superhelical
  • DNA-Binding Proteins
  • Multiprotein Complexes
  • condensin complexes
  • Adenosine Triphosphatases

Associated data

  • BioProject/PRJNA289589