Scientists are using AlphaFold in research to enhance enzymes essential to photosynthesis, paving the way for more heat-tolerant crops.
As droughts and heat waves increase due to global warming, yields of some major crops are decreasing. But what’s happening inside these plants is less visible, and high heat can destroy the molecular machinery that keeps them alive.
At the heart of that machine lies the solar energy process that underpins virtually all life on Earth: photosynthesis. Plants use photosynthesis to produce glucose, the fuel for growth, through a complex movement of enzymes within plant cells. As global temperatures rise, that choreography could break down.
Barkley Walker, an associate professor at Michigan State University, spends his days thinking about how to keep that choreography in line. “Nature already has the blueprint for many enzymes that can respond to heat,” he says. “Our job is to learn from these examples and build the same resilience into the crops we depend on.”
Dr. Walker’s lab focuses on an enzyme essential to photosynthesis called glycerate kinase (GLYK), an enzyme that helps plants recycle carbon during photosynthesis. One hypothesis is that when it gets too hot, GLYK stops working and photosynthesis fails.
Walker’s team set out to find out why. Because the structure of GLYK has never been determined experimentally, we turned to AlphaFold to predict the 3D shape of not only plants but also heat-loving algae that thrive in volcanic hot springs. By taking AlphaFold’s predicted shape and incorporating it into advanced molecular simulations, the researchers were able to observe how these enzymes bend and twist as temperature increases.
That’s when the problem came into focus. The three flexible loops in the plant version of GLYK wobbled and lost their shape in the high temperatures.
Experiments alone could not provide such insights, Walker says. “AlphaFold gave us access to the enzyme structure not available experimentally and helped us identify critical sections for modification.”
Armed with this knowledge, researchers in Walker’s lab created a series of hybrid enzymes that replace the labile loops of plant GLYK with stiffer loops borrowed from algae GLYK. One of these showed excellent performance, remaining stable at temperatures up to 65 °C.
