Members of this protein family are DNA ligases involved in the repair of DNA double-stranded breaks by non-homologous end joining (NHEJ). The system of the bacterial Ku protein (TIGR02772) plus this DNA ligase is seen in about 20 % of bacterial genomes to date and at least one archaeon (Archeoglobus fulgidus). This model describes a central and a C-terminal domain. These two domains may be permuted, as in genus Mycobacterium, or divided into tandem ORFs, and therefore not be identified by this model. An additional N-terminal 3'-phosphoesterase (PE) domain present in some but not all examples of this ligase is not included in the seed alignment for this model; it only represents the central ATP-dependent ligase domain and the C-terminal polymerase domain. Most examples of genes for this ligase are adjacent to the gene for Ku. [DNA metabolism, DNA replication, recombination, and repair]
Jiyao W et al.(2023). "The conserved domain database in 2023.",