Question

Histones are rich in amino acids

• A. Arginine and Histidine
• B. Arginine and Lysine
• C. Valine and Histidine
• D. Lysine and Histidine

Answer 1

The correct option is B

Arginine and Lysine

The correct option is B.

Explanation for correct option:

1. Histones are highly basic proteins that contain abundant arginine and lysine residues.
2. They provide the basic structure around which the DNA strand winds and gives rise to structures known as nucleosomes.
3. Histones can be divided into two groups based on the amino acid content.
4. H1, H2A, and H2B are lysine-rich histones while H3 and H4 are arginine-rich histones.
5. These amino acid components are involved in the condensation and coiling of chromosomes during cell division.

Explanation for incorrect option:

Option A:

1. Arginine is present in high concentrations in the histones.
2. Histones do contain a high proportion of positively charged amino acids such as lysine, arginine, and histidine.

Option C:

1. Histones contain large proportions of basic amino acids such as lysine, arginine, and histidine.
2. Valine is a neutral amino acid.

Option D:

Histones contain a high amount of positively charged amino acids such as lysine, arginine, and histidine.

Final answer: Histones are rich in amino acids - Arginine and lysine.