Q55: The hammerhead ribozyme is one of the most commonly used... - Molecular Biology - Plant Physiology- ICAR JRF/SRF 2024 | Agrigyan

• Hammerhead Ribozyme Mechanism: The hammerhead ribozyme is a small catalytic RNA motif comprising three base-paired helical stems surrounding a conserved core.
• Cleavage Chemistry: It catalyzes a site-specific phosphodiester bond transesterification wherein the 2'-hydroxyl oxygen attacks the adjacent 3'-phosphorus in an in-line $S_N2$ nucleophilic substitution, producing a 2',3'-cyclic phosphate and a 5'-hydroxyl terminus without requiring a protein cofactor.
• Conclusion: Option 2 correctly identifies its cleavage mechanism.

Correct option: (2) It cleaves RNA sequences using a water molecule in a mechanism similar to protein enzymes.