Question

What are histones? What are their functions?

Answer 1

Histones are the basic group of globular proteins that have a high content of basic amino acis, i.e., arginine and lysine. Histones forms the part of the chromosomal material in eukaryotic cells.

There are five types of histone proteins $H_1$, $H_{2}A$,$H_{2}B$, $H_3$, and $H_4$. Four of them $(H_{2}A,H_{2}B,H_{3}and{H}_4)$ occur in pairs to produce histone octamer called Nubody or core of nucleosome.

Functions Histones bear positively charged ends, that attract negetively charged strands of DNA.

Histones provides a medium around which DNA winds, and they play a vital role in gene regulation, as they act as gene repressor. They form the chromatin material and provide stability as are not coagulated by heat.