Low-force DNA condensation and discontinuous high-force decondensation reveal a loop-stabilizing function of the protein Fis.

  title={Low-force DNA condensation and discontinuous high-force decondensation reveal a loop-stabilizing function of the protein Fis.},
  author={Dunja Skoko and Jie Yan and Reid C. Johnson and John F. Marko},
  journal={Physical review letters},
  volume={95 20},
We report single-DNA-stretching experiments showing that the protein Fis, an abundant bacterial chromosome protein of E. coli, mediates a dramatic DNA condensation to zero length. This condensation occurs abruptly when DNA tension is reduced below a protein-concentration-dependent threshold f* < 1 pN. Following condensation, reopening under larger forces proceeds via a series of discrete jumps, indicating that Fis is able to stabilize DNA crossings. Our experiments suggest that Fis may play a… 

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