Genome Structure part 3

  1. histone acetyl-transferases (HATs)
    • enzymes that add acetyl groups to histones
    • an integral part of transcription initiation
    • Adding acetyl will remove the + charge and make the chromatin less condensed
    • Image Upload 1
  2. histone deacetylases (HDACs)
    • group of enzymes that remove the acetyl group from the histone tails
    • Gene inactivation is partly the function of HDACs
    • Image Upload 2
  3. Proteins interacting with methylated histone are involved in __
    • suppression of transcription and generation of heterochromatin
    • makes chromatin more condensed
  4. __ of __ will activate transcription & __ will suppress transcription
    • Acetylation;
    • lysines of H3 & H4;
    • methylation
  5. Acetylation and phosphorylation __ of histone tails, which causes __
    • reduce the positive charge;
    • less affinity of the histone tails for DNA
  6. Formation of __ requires the histone tails. Chemical modification of the tail __
    • 30mm fiber;
    • decreases the ability to make higher order structures of chromatin (which usually represses transcription)
  7. Modification of histones generate binding sites for __. These interacting proteins recruit other proteins that __
    more of and other chromatin modifying enzymes; modify adjacent histones → maintenance and propagation of the modifications (e.g. HATs)
Card Set
Genome Structure part 3
Week 4