BIOL 200 Lecture Notes - Lecture 4: Phosphodiester Bond, Nucleic Acid Double Helix, Bamhi
5 Oct 2017
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Document Summary
Level of condensation affects level of expression. Experiment with globin in chickens: globe gene is not expressed when the chromatin in the area is condensed, and dnase cannot access it. Restriction enzyme bamh1 cuts after a short nuclease sequence, and the global gene is found between 2. Globin gene only sensitive to dnase in cells that express it (decondensed). Identi cation of chromatin regions containing modi ed histone tails (chip) Antibodies speci c for acetylated histone tails recognize these parts and bind to it. Dna binding factors recruit enzymes that modify histone tails. Sequences that bind to dna which are the enhancer/repressors. Resulting modi cations either: promote decondensation, leading to gene activation acetylation, promote condensation, leading to gene repression deacetylation (h3k9 or. Recruitment of histone acetyl transferase to activate speci c genes. Upstream activator sequence (uas) is recognized by the activator during. Hyperacetylation and acetyl groups are added to the n-terminal tails.
