<p>DNA ligases catalyse the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilizing either ATP or NAD(+) as a cofactor [<cite idref="PUB00007386"/>]. This family is a small domain found after the adenylation domain DNA_ligase_N in NAD+-dependent ligases (<db_xref db="INTERPRO" dbkey="IPR001679"/>). OB-fold domains generally are involved in nucleic acid binding.</p> NAD-dependent DNA ligase, OB-fold