The enzyme that joins DNA fragments by forming phosphodiester bonds.
T4 DNA ligase seals nicks by making phosphodiester bonds using ATP; works on sticky and blunt ends. In cells, it joins Okazaki fragments and repairs DNA.
Ligase needs a 5' phosphate and 3' hydroxyl. Sticky ends anneal first by base pairing, then ligase seals the backbone. Alkaline phosphatase prevents vector self-ligation.
Common mistake: ligase joins DNA backbones but does not itself find matching sequences.
The enzyme that joins DNA fragments by forming phosphodiester bonds.
DNA Ligase is one of the 56 topics in Biotechnology & Genomics. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Recombinant DNA, Gene Cloning Workflow, Restriction Enzymes.
Ligation reactions in cloning use a vector to insert ratio of about 1:3.
Work through the Beginner topics in Biotechnology & Genomics first, such as Biotechnology, Genetic Engineering, Selective Breeding, then return to DNA Ligase. Intermediate topics assume the Beginner vocabulary.
The closest topics to DNA Ligase are Recombinant DNA, Gene Cloning Workflow, Restriction Enzymes, Plasmid Vectors. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for DNA Ligase. To practise the whole of Biotechnology & Genomics, use the Biotechnology & Genomics quiz.
DNA Ligase: The enzyme that joins DNA fragments by forming phosphodiester bonds. Recombinant DNA: DNA made by combining sequences from different sources, typically using restriction enzymes and ligase. Read both side by side and note what each one explains.
Ligase joins DNA backbones but does not itself find matching sequences.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Recombinant DNA and explain the difference aloud. Finally, take the Biotechnology & Genomics quiz and come back to this page for any question you miss.
DNA made by combining sequences from different sources, typically using restriction enzymes and ligase.
🧪 Biotechnology & GenomicsCut the gene and vector, ligate, transform bacteria, select colonies and screen for the insert.
🧪 Biotechnology & GenomicsEnzymes that cut DNA at specific sequences, creating sticky or blunt ends for cloning.
🧪 Biotechnology & GenomicsSmall circular DNA carriers with origin of replication, selectable marker and cloning site.
🧪 Biotechnology & Genomics