any of a class of enzymes that act as catalysts in chemical reactions in which molecules are linked together, as in the synthesis and repair of DNA or in the formation of recombinant DNA
See ligase in American Heritage Dictionary 4
(līˈgāsˌ, -gāzˌ)
noun
Any of a class of enzymes that catalyze the linkage of two molecules, generally utilizing ATP as the energy donor. Also called synthetase.