BCHM 218 Study Guide - Quiz Guide: H2Afx, Chromodomain, Cenpa

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Must package 2m of dna into one nucleus while allowing access to factors regulating transcription and replication. Bacteria lack nucleosomes (they do however have abundant histone-like proteins (hu) Histones: possibly allows for faster adaption to environment. Histone tails: histones constitute the largest protein component of chromatin. Contact between histones and dna are mainly between this fold and the phosphodiester backbone or the minor groove of dna. Ineffective in the presence of high level of h1. Chromatosome formation: h1 bind to the nucleosome to form chromatosome, h1 binds an additional 20bp, altering the entry and exit angles of the dna wrapped around the nucleosome, facilitating further compaction. H1 is also known as the linker histone. After addition of h1 to the nucleosome, overall compaction increases to 35- to 40- fold. Flat sides of adjacent nucleosome disks are next to each other. Linker dna (bound to h1) is presumed to bend: zigzag model: