Fis-protein induces rod-like DNA bending

Fis protein can bend DNA chain with length much shorter than its persistence length. We applied single-molecule fluorescence resonance energy transfer method to probe these conformational changes. A broad distribution of end-to-end distances correlates well with the molecular dynamics simulation. The flexibility of DNA upon Fis binding is attributed to the breakages of hydrogen bonds between base pairs. DNA kinks at specific sites, instead of continuous bending. The loosening of DNA structures might have biological implications for the functions of Fis-proteins as transcription cofactors.

161Research highlights►Fis-proteins as transcription cofactors. ►Bending or unzipping proceeding along the DNA helical axis. ►Protein induced DNA kinking with opening motion.