Molecular mechanism by which the nucleoid occlusion factor, SlmA, keeps cytokinesis in check Academic Article uri icon


MeSH Major

  • Bacterial Proteins
  • Carrier Proteins
  • Cytokinesis
  • Cytoskeletal Proteins
  • DNA, Bacterial
  • Escherichia coli
  • Escherichia coli Proteins


  • In Escherichia coli, cytokinesis is orchestrated by FtsZ, which forms a Z-ring to drive septation. Spatial and temporal control of Z-ring formation is achieved by the Min and nucleoid occlusion (NO) systems. Unlike the well-studied Min system, less is known about the anti-DNA guillotining NO process. Here, we describe studies addressing the molecular mechanism of SlmA (synthetic lethal with a defective Min system)-mediated NO. SlmA contains a TetR-like DNA-binding fold, and chromatin immunoprecipitation analyses show that SlmA-binding sites are dispersed on the chromosome except the Ter region, which segregates immediately before septation. SlmA binds DNA and FtsZ simultaneously, and the SlmA-FtsZ structure reveals that two FtsZ molecules sandwich a SlmA dimer. In this complex, FtsZ can still bind GTP and form protofilaments, but the separated protofilaments are forced into an anti-parallel arrangement. This suggests that SlmA may alter FtsZ polymer assembly. Indeed, electron microscopy data, showing that SlmA-DNA disrupts the formation of normal FtsZ polymers and induces distinct spiral structures, supports this. Thus, the combined data reveal how SlmA derails Z-ring formation at the correct place and time to effect NO.

publication date

  • January 5, 2011



  • Academic Article



  • eng

PubMed Central ID

  • PMC3020112

Digital Object Identifier (DOI)

  • 10.1038/emboj.2010.288

PubMed ID

  • 21113127

Additional Document Info

start page

  • 154

end page

  • 64


  • 30


  • 1