SlmA, a nucleoid-associated, FtsZ binding protein required for blocking septal ring assembly over Chromosomes in E. coli

Mol Cell. 2005 May 27;18(5):555-64. doi: 10.1016/j.molcel.2005.04.012.


Cell division in Escherichia coli begins with assembly of the tubulin-like FtsZ protein into a ring structure just underneath the cell membrane. Spatial control over Z ring assembly is achieved by two partially redundant negative regulatory systems, the Min system and nucleoid occlusion (NO), which cooperate to position the division site at midcell. In contrast to the well-studied Min system, almost nothing is known about how Z ring assembly is blocked in the vicinity of nucleoids to effect NO. Reasoning that Min function might become essential in cells impaired for NO, we screened for mutations synthetically lethal with a defective Min system (slm mutants). By using this approach, we identified SlmA (Ttk) as the first NO factor in E. coli. Our combined genetic, cytological, and biochemical results suggest that SlmA is a DNA-associated division inhibitor that is directly involved in preventing Z ring assembly on portions of the membrane surrounding the nucleoid.

Publication types

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

MeSH terms

  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Division / physiology
  • Cell Membrane / metabolism*
  • Chromosomes, Bacterial*
  • DNA Mutational Analysis
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Escherichia coli* / cytology
  • Escherichia coli* / genetics
  • Escherichia coli* / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism


  • Carrier Proteins
  • Escherichia coli Proteins
  • FtsZ84 protein, E coli
  • Recombinant Fusion Proteins
  • SlmA protein, E coli