text: Although the nucleosome is a very stable protein-DNA complex, it is not static and has been shown to undergo a number of different structural re-arrangements including nucleosome sliding and DNA site exposure. Depending on the context, nucleosomes can inhibit or facilitate transcription factor binding. Nucleosome positions are controlled by three major contributions: First, the intrinsic binding affinity of the histone octamer depends on the DNA sequence. Second, the nucleosome can be displaced or recruited by the competitive or cooperative binding of other protein factors. Third, the nucleosome may be actively translocated by ATP-dependent remodeling complexes.