Figure 1
Illustration: Alan Stonebraker

Figure 1: Facilitated diffusion mechanisms in the Berg-von Hippel model. Transcription factors searching for their specific binding site on a DNA chain combine interdomain exchange (decorrelating 3D volume diffusion), intradomain exchange (microhops, short 3D excursions), sliding (1D diffusion along the DNA), and intersegment transfers where the DNA loops back to itself. Inset: Once the transcription factor docks onto its specific binding site it will attract RNA polymerase that produces an RNA copy of the corresponding gene.