Evolution of bifunctional proteins.

The one-gene one-enzyme hypothesis was proposed in the 1940s. This has had to be revisited, in the face of new evidence suggesting that (a) many proteins perform more than one function, and (b) the same peptide chain can fold in more than one conformation, and hence catalyze more than one unique reaction. In this work, we will investigate the evolution of the two distinct functions of such bifunctional proteins.