Parameters affecting the restoration of activity to inactivate mutants of thymidylate synthase via subunit exchange: further evidence that thymidylate synthase is a half-of-the-sites activity enzyme

Results show that the activity restoration in the mutant thymidylate synthase follows a sequential pattern of subunit separation and their subsequent recombination to an active heterodimer. Sequence data of the homo- and heterodimers of the enzyme indicate that the active enzyme is a product of subunit exchange.