Scientists are using AlphaFold in their research to enhance an enzyme necessary for photosynthesis, paving the way for more heat-resistant crops.
As global warming is accompanied by more frequent droughts and heatwaves, harvests of some staple crops are declining. Less visible, however, is what happens inside these plants, where high temperatures can destroy the molecular machinery that keeps them alive.
At the heart of this machinery is a solar-powered process that supports virtually all life on Earth: photosynthesis. Plants use photosynthesis to produce glucose, which fuels their growth through a complex choreography of enzymes inside plant cells. As global temperatures rise, this choreography may break down.
Berkley Walker, an associate professor at Michigan State University, spends his days wondering how to keep up with this choreography. “Nature already has plans for many enzymes that deal with heat,” he says. “Our job is to learn from these examples and build the same resilience in the crops we depend on.”
Walker's lab focuses on an enzyme essential for photosynthesis called glycerate kinase (GLYK), an enzyme that helps plants process carbon during photosynthesis. One hypothesis is that if it gets too hot, GLYK stops working and photosynthesis fails.
Walker's team set out to understand why. Because GLYK's structure had never been determined experimentally, they turned to AlphaFold to predict its three-dimensional shape not only in plants but also in thermophilic algae that thrive in volcanic hot springs. By taking the shapes predicted by AlphaFold and plugging them into sophisticated molecular simulations, researchers could watch the enzymes bend and twist as the temperature increased.
And then the problem came to light: the three elastic loops in the plant version of GLYK lost their shape under the influence of high temperature.
Walker argues that experiments alone could never have provided such insights: “AlphaFold provided access to experimentally inaccessible enzyme structures and helped us identify key sections that needed modification.”
Armed with this knowledge, scientists in Walker's lab created a series of hybrid enzymes that replaced the unstable loops in the GLYK plant with stiffer ones borrowed from the algae's GLYK. One of them performed spectacularly, remaining stable at temperatures up to 65 °C.
