DNA ligase - Definition and Overview

In molecular biology, DNA ligase is an enzyme that repairs broken DNA strands. DNA ligase (EC 6.5.1.1) is a particular type of enzyme that can form covalent phosphodiester bonds and ligate or connect (broken) DNA strands.

An example of how a ligase works (with sticky ends):

5'-AGTCTGATCTGACT        GATGCGTATGCTAGTGCT-3'
3'-TCAGACTAGACTGACTACG        CATACGATCACGA-5'

becomes

5'-AGTCTGATCTGACTGATGCGTATGCTAGTGCT-3'
3'-TCAGACTAGACTGACTACGCATACGATCACGA-5'

External links

• DNA Ligase: PDB molecule of the month (http://nist.rcsb.org/pdb/molecules/pdb55_1.html)