Researchers at Aarhus University have just elucidated structures of a sugar transport protein that drives the transport of sugar in plants. The study provides a comprehensive insight into sugar uptake into plant organs such as flowers, seeds, and fruit. Future research can benefit from these discoveries to address challenges like food security through crop improvement.
In plants, Sugar Transport Proteins (STPs) are key for the uptake of glucose. They are responsible for sugar import into plant organs such as seeds, pollen, and fruit and are essential for correct tissue development. Moreover, controlling sugar uptake through STPs is used by plants as a vital defense strategy against microbial infection, by using starvation and competition for sugar to restrict microbial growth.
The results are a continuation of earlier research at Associate Professor Bjørn Panyella Pedersen's research group at the Department of Molecular Biology and Genetics. A major challenge to make progress in the field is to obtain structures of STPs in different conformations.
Ph.D. Student and first author Laust Bavnhøj explains: “The STPs are highly dynamic membrane proteins that undergo large conformational changes during transport. This flexibility presents a great challenge as conformational stabilization is needed in order to facilitate structure solution by X-ray crystallography. This challenge was exacerbated because we needed the transporter in a very specific conformation in order to answer our questions. Based on our previous work, we could design mutants that worked to destabilize an outward-facing conformation. This allowed us to break the “conformational dead water” and push our protein into a new inward-facing conformation.”
The new work reports two crystal structures of Arabidopsis thaliana STP10. The structures represent two major states needed to understand the complete picture of substrate and proton co-translocation across the cell membrane and into the cell.
Read the complete article at www.mbg.au.dk.