DNA ligase

Definition

DNA ligase is an enzyme that facilitates the joining of DNA strands by catalyzing the formation of a phosphodiester bond. It is essential in DNA replication and repair processes.

5 Must Know Facts For Your Next Test

1. DNA ligase is crucial for sealing nicks in the DNA backbone during replication and recombination.
2. There are different types of DNA ligases, including those specific to bacteria (e.g., T4 DNA ligase) and eukaryotes.
3. In genetic engineering, DNA ligase is used to insert genes into plasmids or other vectors.
4. Mutations or deficiencies in DNA ligase can lead to genetic disorders due to impaired DNA repair mechanisms.
5. ATP or NAD+ are often required as cofactors for the enzymatic activity of DNA ligase.

Review Questions

• What role does DNA ligase play in the process of DNA replication?
• How does DNA ligase contribute to genetic engineering techniques?
• What are the potential consequences of mutations in the gene encoding DNA ligase?

Related terms

DNA Polymerase:

An enzyme that synthesizes new strands of DNA complementary to the template strand.

Restriction Enzyme: An enzyme that cuts DNA at specific recognition nucleotide sequences.

Plasmid:

A small, circular piece of DNA commonly used as a vector for gene insertion in genetic engineering.