Question

Which one of the following modifications is NOT a natural N-terminal modification of proteins?

• A. Acetylation
• B. Benzylation
• C. Myristoylation
• D. Sumoylation

Hint:

Remember that modifications like acetylation and myristoylation are common natural processes for protein regulation, while benzylation is typically associated with synthetic or lab-induced modifications.

Answer 1

The Correct Option is B

Step 1: Understand N-terminal modifications. 
N-terminal modifications occur at the start (N-terminal) of a protein and are important for stability, localization, and function. 
Step 2: Review common natural N-terminal modifications.
Acetylation: A very common natural N-terminal modification.
Myristoylation: Another natural modification where a myristoyl group (fatty acid) is attached to the N-terminal glycine.
Sumoylation: Involves addition of SUMO (Small Ubiquitin-like Modifier) protein and although it can occur at different lysine residues, it is still considered a natural protein modification.
Benzylation: This is not a recognized natural N-terminal protein modification. It is a chemical modification, not commonly found in biological systems. Hence, the correct answer is Benzylation.