Purity > 90% as determined by SDS-PAGE. MW: 77.6kDa. Full Length: 1-671aa. N-terminal 6xHis-tagged. Escherichia coli (strain K12). DNA ligase that catalyzes the formation of phosphodiester linkages between 5'-phosphoryl and 3'-hydroxyl groups in double-stranded DNA using NAD as a coenzyme and as the energy source for the reaction. It is essential for DNA replication and repair of damaged DNA.