DNA ligases catalyse the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilising either ATP or NAD(+) as a cofactor [1]. This domain is the catalytic adenylation domain. The NAD+ group is covalent ...
DNA ligases catalyse the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilising either ATP or NAD(+) as a cofactor [1]. This domain is the catalytic adenylation domain. The NAD+ group is covalently attached to this domain at the lysine in the KXDG motif of this domain. This enzyme- adenylate intermediate is an important feature of the proposed catalytic mechanism [1].
The alpha-helical Nlig-Ia domain is found at the N-terminal of DNA ligases and it has been proposed to either swivel the NAD+ close to the ligase active site lysine on the RAGNYA domain or function as an allosteric NAD+ binding site. The Nlig-Ia doma ...
The alpha-helical Nlig-Ia domain is found at the N-terminal of DNA ligases and it has been proposed to either swivel the NAD+ close to the ligase active site lysine on the RAGNYA domain or function as an allosteric NAD+ binding site. The Nlig-Ia domain is also observed as a solo protein in phages that do not encode a separate NAD+-dependent ligase catalytic module, suggesting the domain can function independently of a DNA ligase. It has been proposed that these domains likely function as NAD+ sensors which might help indicate to the phage the development of NADase host effectors or shield NAD+ from the action of such effectors [1-3].
