DNA ligase activity

Definition

Target type: molecularfunction

Catalysis of the formation of a phosphodiester bond between the 3'-hydroxyl group at the end of one DNA chain and the 5'-phosphate group at the end of another. This reaction requires an energy source such as ATP or NAD+. [ISBN:0716720094]

DNA ligase activity involves the joining of two DNA strands by catalyzing the formation of a phosphodiester bond between the 5'-phosphate group of one nucleotide and the 3'-hydroxyl group of another. This process is crucial for DNA replication, repair, and recombination. In DNA replication, DNA ligase seals the gaps between Okazaki fragments, which are short DNA sequences synthesized on the lagging strand. During DNA repair, DNA ligase joins the ends of broken DNA strands, restoring the integrity of the genetic material. In recombination, DNA ligase is involved in the exchange of genetic information between homologous chromosomes. The mechanism of DNA ligase activity involves the following steps: 1) Binding of the enzyme to the DNA substrate. 2) Activation of the 5'-phosphate group by the enzyme. 3) Formation of a phosphodiester bond between the 5'-phosphate and the 3'-hydroxyl group. 4) Release of the ligated DNA strand. The activity of DNA ligase is tightly regulated by factors such as the availability of ATP, the presence of specific cofactors, and the cellular environment. Mutations in DNA ligase genes can lead to a range of genetic disorders, including Bloom syndrome, Fanconi anemia, and Nijmegen breakage syndrome.'
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Proteins (2)

Compounds (2)