Recreating the synthesis of starch granules in yeast
Recreating the synthesis of starch granules in yeast
复制标题
DOI：
10.7554/elife.15552
复制
发表时间：
2016-11-22
期刊：
影响因子：
7.7
通讯作者：
Zeeman, Samuel C.
中科院分区：
文献类型：
--
作者：
Pfister, Barbara;Sanchez-Ferrer, Antoni;Zeeman, Samuel C.
淀粉作为我国主要农作物的主要营养成分和工业原料，是一种重要的植物产品。它是由葡萄糖聚合物组成的，这些聚合物形成了巨大的半结晶颗粒。其精确的结构和组成决定了其功能和应用；然而，目前还没有通用的模型系统来探索生物合成装置、葡聚糖结构和性质之间的关系。在此，我们在清除了内源性糖原代谢酶的酿酒酵母中表达了拟南芥淀粉生物合成的核心途径。这组生物合成酶的系统变化说明了每种酶是如何影响葡聚糖的结构和溶解度的。全套蛋白的表达产生了致密的、不溶于水的淀粉半结晶结构颗粒，表明该体系确实模拟了淀粉的生物合成。因此，酵母系统具有加速淀粉研究的潜力，并有助于建立对淀粉颗粒生物合成的整体理解，为有针对性的作物生物技术改良提供基础。
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.