Question

What is DNA Packaging? Describe the importance of it.

Answer 1

DNA packaging is an important process in the living cell. A large amount of DNA is tightly packed in the small nucleus of every cell by DNA packaging. During DNA packaging, DNA is wrapped around histones. Histones are proteins that allow DNA to be tightly packaged into units called nucleosomes. Each nucleosome is composed of DNA that is wound 1.65 times around eight histone proteins, namely 2 H2A, 2 H2B, 2 H3 and 2 H4. Nucleosomes are further packaged into a thread like structure called as beads on a string. This 300 nm fibers further compresses and folds to produce a 250 nm-wide fiber, which is tightly coiled into the chromatid of a chromosome.The process ends with the formation of the fiber known as chromatin. Chromatin gives structure to a chromosome. DNA packaging helps the DNA to fit well within the small size of a cell. It also facilitates the easy separation of the correct chromosomes during cell division. Due to highly packed DNA, it is easy to turn genes on or off as per requirement.