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What are restriction enzymes and how are they used to cut DNA?

User Okliv
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Answer and Explanation:

A restriction enzyme is a type of endonuclease enzyme that recognizes a specific short nucleotide sequences on the DNA and cuts the DNA only at palindromic sites. There are different types of restriction enzymes:

1. Type I restriction enzyme – It cuts at sites far from the recognition site and requires both ATP and S-adenosyl- L-methionine as cofactor to function.

2. Type II restriction enzymes – It cleaves at short-specific distances from the recognition site and mostly requires magnesium to function.

3. Type III restriction enzymes – It recognizes two separate non-palindromic sites and cleaves at 20–30 base pairs away from a recognition site. It requires both ATP and S-adenosyl-L-methionine .

The restriction enzymes cleave DNA sequences producing either sticky or blunt ends that can be ligated with other sequences.

User Dleavitt
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