Summary
Novel functions can be evolved in a laboratory in APC superfamily transporters via a single missense mutation in the permeation pathway (1). This was found to occur either by improving weak baseline activity Agp1 or establishing activity for new substrate Put4. These came with a slight fitness cost in the original substrates.
1.
Karapanagioti F, Atlason ÚÁ, Slotboom DJ, Poolman B, Obermaier S. Fitness landscape of substrate-adaptive mutations in evolved amino acid-polyamine-organocation transporters. eLife. 2024;13. Available from: https://doi.org/10.7554/elife.93971