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: Role of histones in DNA packaging.
Histones are basic proteins that help in the packaging of DNA in eukaryotic cells. Their positive charge facilitates interaction with the negatively charged phosphate groups of DNA. Step 2: Amino acids responsible for histone's basic nature.
Histones are rich in basic amino acids, primarily lysine and arginine. These amino acids carry a positive charge, which enhances their binding affinity to the negatively charged DNA. Step 3: Explanation of other options.
Option (A): Incorrect. Glycine and proline are not basic amino acids and do not facilitate DNA-histone interaction. Option (C): Incorrect. Alanine and serine are neutral amino acids and are not involved in DNA binding. Option (D): Incorrect. Aspartic acid and glutamic acid are acidic amino acids, which repel DNA due to their negative charge. \[ \therefore \text{The correct answer is: Lysine and arginine.} \]