NIH Postdoctoral Fellow Rice University Rosharon, Texas
Body of Abstract: Sugars will eventually be exported transporters (SWEETs) are membrane proteins that mediate cellular sugar uptake and efflux, taking a major part in sugar allocation in plants. Despite extensive research on their structures and molecular functions, it is still unclear how SWEETs recognize their substrates. Using SweetTrac1, a biosensor constructed based on the Arabidopsis thaliana SWEET1, we have previously shown the potential of utilizing biosensors and cheminformatics to study the substrate recognition mechanism. Here, we report the new biosensor SweetTrac2, a vacuolar biosensor constructed based on the Arabidopsis thaliana SWEET2, to further explore the connection between the protein’s substrate specificity. The structural comparison of AtSWEET1 and AtSWEET2 along with each transporter’s affinity for different sugars supports the conclusion that substrate recognition by SWEETs is closely connected to non-specific interactions involving key residues in the binding pocket. Furthermore, SweetTrac2 can be an effective tool for monitoring sugar transport at vacuolar membranes that is otherwise challenging to study.