Like Early Starvation 1 and Early Starvation 1 Promote and Stabilize Amylopectin Phase Transition in Starch Biosynthesis
OPEN ACCESS
Loading...
Author / Producer
Date
2023-05
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
OPEN ACCESS
Data
Rights / License
Abstract
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 Arabidopsis plants. We propose a model wherein LESV serves as a nucleating role, with its carbohydrate-binding surfaces helping align glucan double helices to promote their phase transition into semi-crystalline lamellae, which are then stabilized by ESV1. Because both proteins are widely conserved, we suggest that protein-facilitated glucan crystallization may be a general and previously unrecognized feature of starch biosynthesis.
Permanent link
Publication status
published
External links
Editor
Book title
Journal / series
Volume
9 (21)
Pages / Article No.
Publisher
AAAS
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
Organisational unit
03707 - Zeeman, Samuel C. / Zeeman, Samuel C.
Notes
Funding
182570 - Understanding the Cell Biology of Starch Metabolism in Plants (SNF)