Question

Which amino acids are histones rich in, facilitating their interaction with DNA?

• A. Glycine and proline.
• B. Lysine and arginine.
• C. Alanine and serine.
• D. Aspartic acid and glutamic acid.

Hint:

Histones are rich in basic amino acids like lysine and arginine, which facilitate their interaction with the negatively charged DNA.

Answer 1

The Correct Option is B

Step 1: Histone Function in DNA Packaging.
Histones are fundamental proteins in eukaryotic cells responsible for compacting DNA. Their inherent positive charge enables electrostatic attraction to the DNA's negatively charged phosphate backbone.Step 2: Amino Acid Composition of Histones.
Histones exhibit a high abundance of basic amino acids, specifically lysine and arginine. These amino acids contribute the positive charge essential for strong binding to DNA.Step 3: Evaluation of Alternative Options.
Option (A): Invalid. Glycine and proline are not basic amino acids and thus do not contribute to DNA-histone binding. Option (C): Invalid. Alanine and serine are neutral amino acids and play no role in DNA interaction. Option (D): Invalid. Aspartic acid and glutamic acid are acidic amino acids, possessing a negative charge that repels DNA.\[\therefore \text{The correct answer is: Lysine and arginine.}\]