  We study the impact of DNA coiling on the search rate of proteins moving
along the DNA contour interspersed by three-dimensional (3D) bulk excursions.
When the DNA is coiled proteins performing short 3D hops along a DNA segment
can be captured by foreign DNA segments that have looped back close to the
original segment. These intersegmental jumps are shown to enhance the search
rate for a specific site on the DNA by lowering the tendency to resample
previously visited sites on the DNA. The model developed here offers a
quantitative description of recent single molecule experiments on facilitated
diffusion of restriction enzymes EcoRV.
