The energetic cost of bending short segments of DNA is very high. This bending 
is critical for the packaging of DNA and is exploited to regulate many cellular 
processes. In prokaryotes, IHF and HU are key architectural proteins present at 
high concentrations. New protein-DNA co-crystal structures, and the adaptation 
of advanced biophysical and biochemical techniques have led to an improved 
understanding of how these proteins interact with DNA. These techniques include 
time-resolved synchrotron X-ray footprinting, differential scanning calorimetry, 
isothermal titration calorimetry and single-molecule experiments.