Histone Acetyl Transferases: Difference between revisions
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=== Overview === | === Overview === | ||
HATs or histone | HATs or [[histone|histone]] [[acetyltransferases|acetyltransferases]], are [[Enzymes|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|lysine]] [[Amino_acids|amino acids]] on histone [[proteins|proteins]]. The [[positive charge|positive charge]] of the lysine once acetylated, (the enzyme transfers an [[acetyl group|acetyl group]] from [[Acetyl-CoA|acetyl-CoA]]), is neutralised. This is important as it reduces the affinity between the histone and [[DNA|DNA]], as it is negatively charged, which makes the DNA more accessible to other [[transcription factors|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|chromatin]] structure so in addition to this the conformation change also produces protein-protein interaction domains called [[bromodomains|bromodomains]]. These bromodomains promote [[transcription|transcription]] as [[Bdf1|Bdf1]] binds acetylated H4, and therefore recruits [[TFIID|TFIID]] a subunit (TAFII250) of which also binds to the acetylated H4. | ||
=== History === | === History === | ||
In the | In the 1960s a correlation between acetylation and transcription was discovered. The first HAT was shown to be homologous to [[GCN5|GCN5]] in [[yeast|yeast]], which was a monumental discovery as GCN5 was already known to function as a transcriptional activator<ref>Legube, G. and Trouche, D. (2003). Regulating histone acetyltransferases and deacetylases. EMBO reports, 4(10), pp.944-947.</ref>. | ||
=== References === | === References === | ||
<references /> | <references /> | ||
Revision as of 07:11, 18 October 2018
Overview
HATs or histone acetyltransferases, 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 1960s 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].