Question

How do these enzymes function?

Hint:

Restriction enzymes always cut at a specific point between the same two bases on the opposite strands (e.g., EcoRI cuts between G and A).

Answer 1

Step 1: Understanding the Concept:
Restriction enzymes act with high specificity to manipulate DNA for genetic engineering.
Step 2: Detailed Explanation:
The mechanism of action for a restriction endonuclease is as follows:
1. Inspection: The enzyme scans the DNA molecule to find its specific recognition site.
2. Binding: Once the site is found, it binds to the DNA.
3. Cleavage: It cuts both strands of the double helix. Most enzymes cut slightly away from the center of the palindrome, between the same two bases on both strands.
4. Sticky Ends: This often leaves overhanging single-stranded stretches called "sticky ends," which facilitate the joining of DNA fragments using DNA ligase.
Step 3: Final Answer:
They recognize specific palindromic sites and cut the sugar-phosphate backbone of both DNA strands to create fragments.