BIOL 483 Lecture Notes - Lecture 55: Epigenetics, H3K4Me3, Conformational Change
Document Summary
Dnmt3a has catalytic domain (mtase) blocked by add (autoinhibitory domain) and there is no catalytic activity. Simultaneously add can"t bind to h3k4me3 mark so this is in autoinhibited state. When add binds to unmethylated h3k4 -> conformational chain to unblock mtase -> allow catalytic activity to proceed. Not only does de novo transferase but also dnmt1. Complicated figure but ther"es the replication fork on the left with the bottom tstrand being hemimehtylated dsdna, parental strand has methylated mark but newly synthesised strand doesn"t have methylated mark. We are multicellular diploid organisms in case of humans it"s 2n = 46 chromosomes. Germ cells (sperm, egg) = haploid = n. From somatic cells through meiosis there are haploid gametes that are generated and come together in fertilisation to form diploid zygote and then mitosis and thne multicullular diploid organism formed. Imprinted genes = genes expressed from only one parent specific allele. Stratrt from primordial germ cells arisen from adult diploid humans.
