BIOL 3110 Study Guide - X-Inactivation, Histone H3, H2Afy
Document Summary
Protein scaffold- with respect to protein scaffolding, there is a specific complementary sequence required for binding to dna while there is no specific sequence needed for histone binding to. The sequence specificity of protein scaffolds may lead to different sized loops in dna. Epigenetic inheritance = inheritance of protein structure rather than from a dna sequence. A form of inheritance superimposed on the genetic inheritance based on dna. Position effects- the activity of a gene depends on its position relative to a nearby region of heterochromatin on a chromosome. Lysine is present in high concentrations in histones. Modification: cis vs. trans modifications just by binding the modifier, there is a direct effect on the structure. Wrapped neucleosomes last for 250 msec while unwrapped neucleosomes last for 10-50 msec. During this unwrapped phase, sequence specific dna binding proteins can bind to binding sites on dna. This means that chromatin structure can effect gene expression.
