Portal de Periódicos da CAPES

Recreating the synthesis of starch granules in yeast

2016; eLife Sciences Publications Ltd; Volume: 5; Linguagem: Inglês

10.7554/elife.15552

2050-084X

Barbara Pfister, Antoni Sánchez‐Ferrer, Ana Díaz, Kuan‐Jen Lu, Caroline Otto, Mirko Holler, Farooque Razvi Shaik, Florence Meier, Raffaele Mezzenga, Samuel C. Zeeman,

Enzyme Production and Characterization

Starch, as the major nutritional component of our staple crops and a feedstock for industry, is a vital plant product. It is composed of glucose polymers that form massive semi-crystalline granules. Its precise structure and composition determine its functionality and thus applications; however, there is no versatile model system allowing the relationships between the biosynthetic apparatus, glucan structure and properties to be explored. Here, we expressed the core Arabidopsis starch-biosynthesis pathway in Saccharomyces cerevisiae purged of its endogenous glycogen-metabolic enzymes. Systematic variation of the set of biosynthetic enzymes illustrated how each affects glucan structure and solubility. Expression of the complete set resulted in dense, insoluble granules with a starch-like semi-crystalline organization, demonstrating that this system indeed simulates starch biosynthesis. Thus, the yeast system has the potential to accelerate starch research and help create a holistic understanding of starch granule biosynthesis, providing a basis for the targeted biotechnological improvement of crops.