BIOL 483 Lecture Notes - Lecture 31: H2Afz, Alternative Splicing, Chromatin Remodeling
Document Summary
Acidic patch = formed when h2a, h2b interacts, important for stabilising histone-histone contacts with h4 in nucleosome. L1 loops = sequences in c terminal tail that facilitate interaction between 2 h2a proteins in nucleosome , h2a-h2a self-interaction domain. L2 loops = interacts with nucleosomal dna, solvent accessible. More polar and acidic residues at c terminal tail than on canonical h2a. > different amino acid sequence from canonical h2a -> weaker contacts with h3/h4. > these differences affect docking domain where h2a c terminal tail extends into h3, Chaperones (eg. anp32e for h2a. z chromatin removal at sites of dna damage) and remodelers (eg. p400, srcap for h2a. z deposition) important for h2a. z deposition. Homotypic h2a. z more stable than heterotypic h2a. z because of large acidic patch (stronger interactions with h4) and no clashing of l1 loop in n terminal region. H2a. z = 3 diff proteins encoded by 2 genes and one splice variant that can be distinguished by chromatin remodelers, h2a. z. 1, h2a. z. 2. 1, h2a. z. 2. 2.
