Q46: Which of the following restriction endonuclease pairs are isochizomers? - Plant Biotechnology / Genetic Engineering - Biochemistry- ICAR JRF/SRF 2024 | Agrigyan

• Definition of Isoschizomers: Restriction endonucleases that recognize the identical target nucleotide sequence.
• Hpall and Mspl: Both enzymes recognize the tetranucleotide palindromic sequence $5'\text{-CCGG-3'}$. They differ in methylation sensitivity: HpaII is inhibited if the internal cytosine is methylated ($5'\text{-C}^m\text{CGG-3'}$), whereas MspI cleaves whether the internal cytosine is methylated or unmethylated, making them indispensable tools for studying DNA methylation.
• Neoschizomers: Enzymes that recognize the same sequence but cleave at different positions.

Correct option: (2) Hpall and Mspl