What is Curved DNA? - Biology

I'm hardly an authority on this topic, but I distinctly recall an amazing report the mid-1990s of the co-crystal structure the yeast TATA binding protein in complex with DNA. The structure shows that TBP bends the DNA axis by approximately 80 degrees, presumably in order to expose bases and improve recognition. The structure is available at RCSB: http://www.rcsb.org/pdb/explore.do?structureId=1ytb . (Make sure you check out the Jmol view.)

Thermodynamically speaking, bending DNA would require energy. Therefore, DNA that was pre-bent (e.g., due to auxiliary binding proteins or composition bias) would improve binding.

So, I suspect that in the context DNA binding proteins, "curved" refers to the static curvature of unbound DNA or to the bending of DNA upon binding in order to facilitate recognition.