DNA ligases, essential for genomic stability, repair single- and double-strand breaks in DNA. Human genes LIG1, LIG3, and LIG4 encode ATP-dependent ligases, with unique cellular functions dictated by specific protein interactions. LigI and LigIV operate exclusively in the nucleus, while alternative translation yields mitochondrial and nuclear LigIIIα, along with germ cell-specific LigIIIβ. Interestingly, LigIII’s closer relation to poxvirus ligases than LigI and LigIV is notable. Understanding these ligases’ structures, catalytic activities, and roles in diverse DNA transactions, as well as their implications in human diseases, forms the focus of this study.
