A certain regulatory gene is involved in controlling the expression of other genes. In studying this regulatory gene, a scientist discovers that it encodes for an enzyme that causes histone deacetylase (the removal of acetyl groups from histone tails). Based on this information, how would you predict that this enzyme regulates gene expression?

Question

anonymous · Answer

this is an eg of epigenetic regulation of gene expression . acetylation of histones in nucleosomes causes them to unwind the DNA , making the promoters of  genes available to trancription factor binding and thus switching on these genes. Histone deacetylation causes the nucleosomes to tightly wrap the DNA around themselves making the promoters unavailable for trancription factor binding causing the genes to switch off.

Histone acetylation is mediated by HATs ( Histone Acetyl Transferases )and deacetylation by HDACs (Histone Deacetylases)

This is negative regulation of gene expression as the genes are being switched off.