Who were responsible for the isolation of "methylase" kind of enzyme from E coli in 1960's ?

Options

A. Cohen and Boyer
B. Banting and Best
C. Linn and Arber
D. Smith and Wilcox

Answer

**Step-by-Step Solution:**

1. **Understanding Methylase**: Methylase is an enzyme that adds a methyl group to DNA bases such as adenine and cytosine. This modification plays a crucial role in protecting the DNA from degradation by restriction enzymes (endonucleases).

2. **Role of Restriction Enzymes**: Restriction enzymes are proteins that cut DNA at specific sequences. The presence of methylase helps protect the bacterial DNA from being cut by these enzymes, which is essential for the survival of the bacteria.

3. **Restriction-Modification System**: The combination of restriction enzymes and their corresponding methylases constitutes a restriction-modification system. This system is a defense mechanism for bacteria against foreign DNA, such as that from bacteriophages (viruses that infect bacteria).

4. **Isolation of Methylase**: In the 1960s, researchers Lin and Harper were responsible for the isolation of the methylase enzyme from E. coli. Their work contributed significantly to our understanding of the restriction-modification system in bacteria.

5. **Conclusion**: The correct answer to the question of who isolated the methylase enzyme from E. coli in the 1960s is Lin and Harper.

**Final Answer**: Lin and Harper were responsible for the isolation of the methylase enzyme from E. coli in the 1960s.

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