Question

Histone proteins are

• A. basic, negatively charged
• B. basic, positively charged
• C. acidic, positively charged
• D. acidic, negatively charged

Answer 1

Answer: (B)

In eukaryotes, $DNA$ organisation is complex. There is a set of positively charged, basic proteins called histones. Histones are rich in the basic amino acid residues lysine and arginine. 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 $H_4$) produce histone octamer called nu body or core of nudeosome. The negatively charged $DNA$ is wrapped around the positively charged histone octamer to form nudeosome. $DNA$ connecting two adjacent nudeosomes is called linker $DNA$ which bears $H_1$ histone proteins.