Histone acetyltransferases (HATs) are the workhorses of the epigenome. These enzymes have a huge role epigenetic regulation of gene expression. 1 Avvakumov, N., and Cote, J. (2007). 2  The MYST family of histone acetyltransferases and their intimate links to cancer. 3  Oncogene 26, 5395-5407. 4  Crump, N.T., Hazzalin, C.A., Bowers, E.M., Alani, R.M., Cole, P.A., and Mahadevan, L.C. (2011). Type A HATs are found in the nucleus and are responsible for acetylation of histones in chromatin. Type B HATs are found in the cytoplasm and acetylate newly translated histones to facilitate their assembly into nucleosomes (Richman et al., 1988) . HATs can also be put into more defined categories based on structural and functional similarity of their catalytic domains. 1 Avvakumov, N., and Cote, J. (2007). 2  The MYST family of histone acetyltransferases and their intimate links to cancer. 3  Oncogene 26, 5395-5407. 4  Crump, N.T., Hazzalin, C.A., Bowers, E.M., Alani, R.M., Cole, P.A., and Mahadevan, L.C. (2011). DNA is organized by its incorporation into chromatin, the basic subunit of chromatin being the nucleosome. A nucleosome is composed of 147 base pairs of DNA coiled around an octamer of histone proteins, two molecules each of histone H2A, H2B, H3 and H4. There is a recent and growing body of evidence linking histone acetylation to DNA replication and repair. One of the first studies suggesting a link between acetylation and DNA repair came from a genetic study of histone H4 acetylation in yeast. Histone acetyltransferases (HATs) are enzymes that acetylate conserved lysine amino acids on histone proteins by transferring an acetyl group from acetyl CoA to form ε- N-acetyllysine. DNA is wrapped around histones, and, by transferring an acetyl group to the histones, genes can be turned on and off. In general, histone acetylation increases gene expression. In general, histone acetylation is linked to transcriptional activation and associated with euchromatin. The basic mechanism catalyzed by HATs involves the transfer of an acetyl group from acetyl-CoA to the ε-amino group of a target lysine side-chain within a histone. Different families of HATs employ unique strategies in order to effect such a transformation. Histone acetyltransferases can also acetylate non-histone proteins, such as nuclear receptors and other transcription factors to facilitate gene expression. The basic mechanism catalyzed by HATs involves the transfer of an acetyl group from acetyl-CoA to the ε-amino group of a target lysine side-chain within a histone. Different families of HATs employ unique strategies in order to effect such a transformation. These reactions are typically catalysed by enzymes with  histone acetyltransferase  (HAT) or  histone deacetylase  (HDAC) activity. Acetylation is the process where an acetyl functional group is transferred from one molecule (in this case, Acetyl-Coenzyme A) to another. Acetylation has the effect of changing the overall charge of the histone tail from positive to neutral. Nucleosome formation is dependent on the positive charges of the H4 histones and the negative charge on the surface of H2A histone fold domains. histone / histones. Under the microscope in its extended form, chromatin looks like beads on a string. The beads are called nucleosomes. Each nucleosome is made of DNA wrapped around eight histone proteins that function like a spool and are called a histone octamer. Each histone octamer is composed of two copies each of the histone proteins H2A, H2B, H3, and H4. Histone acetylation and deacetylation are the processes by which the lysine residues within the N-terminal tail protruding from the histone core of the nucleosome are acetylated and deacetylated as part of gene regulation. Histone acetylation and deacetylation are essential parts of gene regulation. Acetylation has the effect of changing the overall charge of the histone tail from positive to neutral. Nucleosome formation is dependent on the positive charges of the H4 histones and the negative charge on the surface of H2A histone fold domains. Histone acetyltransferases serve many biological roles inside the cell. Chromatin is a combination of proteins and DNA found in the nucleus, and it undergoes many structural changes as different cellular events such as DNA replication, DNA repair, and transcription occur. The basic mechanism catalyzed by HATs involves the transfer of an acetyl group from acetyl-CoA to the ε-amino group of a target lysine side-chain within a histone. Different families of HATs employ unique strategies in order to effect such a transformation. Histones are a family of basic proteins that associate with DNA in the nucleus and help condense it into chromatin. Nuclear DNA does not appear in free linear strands; it is highly condensed and wrapped around histones in order to fit inside of the nucleus and take part in the formation of chromosomes. Each histone octamer is composed of two copies each of the histone proteins H2A, H2B, H3, and H4.
http://epigenie.com/key-epigenetic-players/chromatin-modifying-and-dna-binding-proteins/histone-acetyltransferases-hats/ http://epigenie.com/key-epigenetic-players/chromatin-modifying-and-dna-binding-proteins/histone-acetyltransferases-hats/ http://epigenie.com/epigenie-learning-center/epigenetics/histone-acetylation-and-genome-function/ https://en.wikipedia.org/wiki/Histone_acetyltransferase https://en.wikipedia.org/wiki/Histone_acetyltransferase https://en.wikipedia.org/wiki/Histone_acetylation_and_deacetylation http://www.nature.com/scitable/definition/histone-histones-57 https://en.wikipedia.org/wiki/Histone_acetylation_and_deacetylation https://en.wikipedia.org/wiki/Histone_acetyltransferase http://www.nature.com/scitable/definition/histone-histones-57
what are the functions of histone acetyltransferases