Year: 2020
Type: article
Abstract: As nucleotidyl transferases, formation of a covalent enzyme-adenylate intermediate is a common first step of all DNA ligases. While it has been shown that eukaryotic DNA ligases utilize ATP as the adenylation donor, it was recently reported that human DNA ligase IV can also utilize NAD+ and, to a lesser extent ADP-ribose, as the source of the adenylate group and that NAD+, unlike ATP, enhances ligation by supporting multiple catalytic cycles. Since this unexpected finding has significant implications for our understanding of the mechanisms and regulation of DNA double strand break repair, we attempted to confirm that NAD+ and ADP-ribose can be used as co-factors by human DNA ligase IV. Here, we provide evidence that NAD+ does not enhance ligation by pre-adenylated DNA ligase IV, indicating that this co-factor is not utilized for re-adenylation and subsequent cycles of ligation. Moreover, we find that ligation by de-adenylated DNA ligase IV is dependent upon ATP not NAD+ or ADP-ribose. Thus, we conclude that human DNA ligase IV cannot use either NAD+ or ADP-ribose as adenylation donor for ligation.
Source: Nucleic Acids Research
DOI: 10.1093/nar/gkaa1118
Language: English
Topic: DNA Repair Mechanisms
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,992
Awards: Cellular Functions of Eukaryotic DNA Ligases, Mechanisms of Human Lymphoid Chromosomal Translocation, Mechanism and Regulation of Human Nonhomologous DNA End Joining, G9000039817, G9000052453, G9000108948, G9000115479, University of New Mexico Cancer Center Support Grant, Structural Cell Biology of DNA Repair Machines, Site-Specific Recombination in Human Health & Disease, University of Southern California Norris Comprehensive Cancer Center Support Grant (CCSG)
OpenAlex ID: W3107404870