BIOL 230W Lecture Notes - Lecture 4: Histone H1, Histone H2A, Heterochromatin
Document Summary
Biol 230w lecture 4 dna structure. Double helix resulting from two twisted single strands. Results in a major (large) and minor (small) groove) Grooves play an important role in protein binding. Nucleases: cut dna: protect bacteria from viruses (used in recombinant dna technology) Topoisomerases: cuts one strand to release rotational tension and then rejoins dna: joins 3" -oh with 5" phosphate. Helicase: use atp to break down hydrogen bonds between bases (unzips) Chromatin: complex of proteins and dna to help pack dna. Chromatin structure varies during cell cycle: interphase = euchromatin: loose, actively transcribed, heterochromatin: tightly packed, inactive, more histones present. Dna in dynamic association with histone core proteins.
