Authors: Chun Liu, Barbara Pfister, Rayan Osman, Maximilian Ritter, Arvid Heutinck, Mayank Sharma, Simona Eicke, Michaela Fischer-Stettler, David Seung, Coralie Bompard, Melanie R. Abt, Samuel C. Zeeman
Published: 2023-05-26
Source: Full article
Starch, the most abundant carbohydrate reserve in plants, primarily consists of the branched glucan amylopectin, which forms semi-crystalline granules. Phase transition from a soluble to an insoluble form depends on amylopectin architecture, requiring a compatible distribution of glucan chain lengths and a branch-point distribution. Here, we show that two starch-bound proteins, LIKE EARLY STARVATION 1 (LESV) and EARLY STARVATION 1 (ESV1), which have unusual carbohydrate-binding surfaces, promote the phase transition of amylopectin-like glucans, both in a heterologous yeast system expressing the starch biosynthetic machinery and in