A plant enzyme - ATP synthase - has evolved a new function by changing a single protein.
ATP synthases works during the day to store energy the plants creates via photosynthesis. At night, ATP synthase shuts down to prevent the plant from using energy.
With the protein change, the enzyme can not only work at night, but preforms an entirely different function by transporting energy to the plant roots.
Scientists describe the extra function of the enzyme as a food processor where you can swap attachments for different functions.Read more at Michigan State University