Elusive Z- DNA Found On Nucleosomes

New Research Found  that left-handed Z-DNA, normally only found at sites where DNA is being copied, can also form on nucleosomes.The structure of DNA which provides the blueprint for life has famously been described as a double helix. To save space inside the nucleus, DNA is tightly wound around proteins to form nucleosomes which are then further wound and compacted into chromatin, which is further compacted into chromosomes.But this familiar image of a right handed coil (also called B-DNA) is not the only form of DNA. At sites where DNA is being copied into RNA (the messenger which is used as the instruction to make proteins) the DNA needs to unwind, and, in a process of negative supercoiling, can form a left-handed variety of the DNA double helix (Z-DNA)see more