Histone Acetyl Transferases: Difference between revisions
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=== Overview === | === Overview === | ||
HATs or histone acetyl transferases, are enzymes that play a role in transcription activation, and are known to function in multi-subunit complexes of two main types; GNAT and MYST. They work by acetylating lysine amino acids on histone proteins. The positive charge of the lysine once acetylated, (the enzyme transfers an acetyl group | HATs or histone acetyl transferases, are enzymes that play a role in transcription activation, and are known to function in multi-subunit complexes of two main types; GNAT and MYST. They work by acetylating lysine amino acids on histone proteins. The positive charge of the lysine once acetylated, (the enzyme transfers an acetyl group from acetyl-CoA), is neutralised. This is important as it reduces the affinity between the histone and DNA, as it is negatively charged, which makes the DNA more accessible to other transcription factors<ref>Lodish, H. (2016). Molecular cell biology. 7th ed. New York: W. H. Freeman and Co., p.260.</ref>. However, this does not produce enough acetylation to impact chromatin structure so in addition to this the conformation change also produces protein-protein interaction domains called bromodomains. These bromodomains promote transcription as Bdf1 binds acetylated H4, and therefore recruits TFIID a subunit (TAFII250) of which also binds to the acetylated H4. | ||
=== History === | === History === | ||
Revision as of 21:50, 17 October 2018
Overview
HATs or histone acetyl transferases, are enzymes that play a role in transcription activation, and are known to function in multi-subunit complexes of two main types; GNAT and MYST. They work by acetylating lysine amino acids on histone proteins. The positive charge of the lysine once acetylated, (the enzyme transfers an acetyl group from acetyl-CoA), is neutralised. This is important as it reduces the affinity between the histone and DNA, as it is negatively charged, which makes the DNA more accessible to other transcription factors[1]. However, this does not produce enough acetylation to impact chromatin structure so in addition to this the conformation change also produces protein-protein interaction domains called bromodomains. These bromodomains promote transcription as Bdf1 binds acetylated H4, and therefore recruits TFIID a subunit (TAFII250) of which also binds to the acetylated H4.
History
In the 1960’s a correlation between acetylation and transcription was discovered. The first HAT was shown to be homologous to GCN5 in yeast, which was a monumental discovery as GCN5 was already known to function as a transcriptional activator[2].