Hypersensitive site

In genetics a hypersensitive site is a short region of chromatin and is detected by its super sensitivity to cleavage by DNase I and other various nucleases (DNase II and micrococcal nucleases).

In a hypersensitive site, the nucleosomal structure is less compacted, increasing the availability of the DNA to binding by proteins, such as transcription factors and DNase I.

Note: hypersensitive sites precede active promoters.

Hypersensitive sites are generated as a result of the binding of transcription factors that displace histone octamers.

The distance from the known restriction site to the DNase cut is then measured to give the location.