Restriction endonucleases

Definition

Restriction endonucleases are enzymes that cut DNA at specific nucleotide sequences, known as restriction sites. They are essential tools in molecular cloning, genetic mapping, and various DNA manipulation techniques.

5 Must Know Facts For Your Next Test

1. Restriction endonucleases recognize palindromic sequences in DNA.
2. They can create either blunt ends or sticky ends when they cut DNA.
3. First discovered in bacteria, these enzymes serve as a defense mechanism against viral DNA.
4. Over 3,000 restriction endonucleases have been identified and characterized.
5. They require magnesium ions (Mg2+) as cofactors for their enzymatic activity.

Related terms

Ligase: An enzyme that joins two strands of DNA together by forming a phosphodiester bond.

Palindromic Sequence: A sequence of base pairs that reads the same backward and forward on complementary strands.

Molecular Cloning: The process of making multiple copies of a specific DNA segment using living cells.