Encyclopedia > Histone

  Article Content

Histone

Histones are chromosome proteins that act as spools around which DNA winds, thus facilitating the compaction necessary to fit the largegenomes of eukaryotes inside cell nuclei. Five histone types are known (H1, H2A, H2B, H3, and H4). Two each of H2A, H2B, H3, and H4 are assembled to form a nucleosome together with DNA, thereby packing it tight. H1 is needed for histone-DNA-complexes to form a 30-nm fiber, which packs the DNA even more tightly. In general, genes that are active have less bound histone, while inactive genes are highly associated with histones during interphase.

See also: gene silencing, genetics



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
East Islip, New York

... 45 to 64, and 11.8% who are 65 years of age or older. The median age is 37 years. For every 100 females there are 95.2 males. For every 100 females age 18 and over, ...

 
 
 
This page was created in 23.4 ms