ABSTRACT
The histone tails are positively charged and the acetyl group that is transferred carries a negative charge along, leading in sum to the reduction of the charge of the histone tail. The complexity of the histone tail modifications is the result of the existence of a large variety of families of histone modifying enzymes which are commonly grouped as histone writers, readers and erasers. Histone tails—for their build-up, as is currently more and more realized, also the histone cores are the substrate of a large number of post-translational modifications (PTMs). One of the most important families of histone enzymes is based on the bromodomains which are linked to histone tail acetylations. The ATPase unit of chromatin remodelers is related to helicases from the SNF2 family which are molecular motors that open DNA double strands; remodelers have evolved to unpeel the DNA from the histone octamer.
