Researchers compared the proteins of a thermophilic fungus (in red) with those of a mesophilic fungus (in blue) to understand how some fungi grow at high temperatures. Credit: Ragothaman M Yennamalli
Researchers have deciphered how changes in the structure of specific proteins make some fungi able to adapt and grow at high temperatures1.
The proteins are enzymes that break down carbohydrates such as polysaccharides. A team at the SASTRA Deemed to be University in Tamil Nadu found that the proteins retain a stable structure at the core region, allowing fungi to thrive in warm environments.
It is possible to introduce the properties of the heat-tolerant proteins into proteins that can convert complex polysaccharides into glucose at low temperatures, say the scientists. This would reduce the costs of glucose production in industries.
Generally, fungi do not grow optimally at high temperatures, but some do. To find out why, the researchers compared the proteins of a thermophilic fungus (Chaetomium thermophilum) with those of a mesophilic fungus (Chaetomium globosum). They modelled the proteins using sequence-based analysis and a deep learning technique.
The team, led by Ragothaman M. Yennamalli, found structural changes on the exposed surface of the proteins in both fungi. Hydrophobic interactions, which impart stability to proteins, increased in the heat-stable proteins. These proteins also showed a significant increase in hydrogen bonds and other interactions.
In bacterial proteins, salt bridges and charged residues allow them to tolerate heat. The researchers say a similar mechanism may be at play in fungal proteins. “An important industrial application of this research is to genetically engineer plants to express specific heat-tolerant fungal proteins for biofuel production,” says Yennamalli.
