Understanding the Molecular Players Involved in Creating Parts of Plant Cell Walls

March 13, 2023
By Emily Nelson

Insights into an enzyme’s mechanism could have bioenergy applications 

The Science    

Plant cell walls are made up of several complex carbohydrates, molecules that store and supply energy. However, there is a lot we don’t know about how these carbohydrates are made. This is mostly because they are made by enzymes that are still being studied. 

Galactan synthases are enzymes that play a role in creating an important carbohydrate found in plant cell walls. Researchers reported the crystal structure of Galactan Synthase 1, gaining a better understanding of the enzyme’s architecture and mechanism. This information could help scientists use this enzyme for a variety of bioenergy applications. 

The Impact

Scientists are interested in designing plant cell walls that have improved properties so they can use the carbon locked within them for the production of sustainable biochemicals and biofuels. Accomplishing this will require an understanding of the processes within plant cell walls at a molecular level. The results of this study improve our understanding of Galactan Synthase 1 and its role in producing an important carbohydrate in plant cell walls. This is only the third enzyme structure involved in plant cell wall biosynthesis that has been solved. 


Researchers from the Center for Bioenergy Innovation and the Joint BioEnergy Institute investigated the structure and function of the Galactan Synthase 1 (GalS1) enzyme from poplar. GalS enzymes are involved in the synthesis of pectic rhamnogalacturonan I (RGI), a complex carbohydrate found in cell walls in all plants. By determining the structure of GalS1, the researchers have provided the first structural information for an enzyme in the GT92 family, of which GalS1 is a part. The study provides detailed insight into the function of GT92 enzymes and suggests a new model for how RGI is synthesized. 

Publication: Prabhakar, P.K., Pereira, J.H., Taujale, R. et al. Structural and biochemical insight into a modular β-1,4-galactan synthase in plants.Nature Plants (2023). [DOI: 10.1038/s41477-023-01358-4.]