Core Proteins

Why is it necessary to package DNA?
The DNA is around 3 meters long and must fit into the nucleus, which is only a few micrometers in diameter. The DNA molecules must be packed into an incredibly compressed and compact structure called chromatin to fit into the nucleus. The DNA is reduced to an 11 nm fiber during the earliest phases of packaging, which represents approximately 5-6 folds of compaction. This is accomplished by packaging nucleosomes in a specific order. DNA packaging is divided into three categories.
1. The nucleosome is the first-order DNA packing.
2. Solenoid fiber is a type of second-order DNA packing.
3. Scaffold loop Chromatids Chromosome is the third order DNA packaging.