在同位三元复合体中SWEET转运体的结构
Yuyong Tao1, Lily S Cheung2, Shuo Li1,3
1Department of Molecular and Cellular Physiology, 279 Campus Drive, Stanford University School of Medicine, Stanford, CA 94305, USA.
Nature
|October 20, 2015
概括
米OsSWEET2b是一种真空葡萄糖输送器,形成具有独特的三螺旋束结构的剪切物. 这种结构揭示了糖运输机制的洞察力以及在真核生物中工程糖流的潜在应用.
科学领域:
- 生物化学
- 分子生物学
- 植物科学
背景情况:
- 细胞使用三大家族的蛋白质来运输糖:MFS,SSF和SWEET.
- 植物SWEET对于糖转移至关重要,影响蜜液分泌,花载荷,花粉和种子发育.
- 植物甜味剂可以通过糖泄漏影响病原体的敏感性.
研究的目的:
- 阐明米真空葡萄糖输送器OsSWEET2b的结构和功能.
- 了解由SWEET蛋白调解的糖转移的分子机制.
- 确定工程糖流的潜在目标.
主要方法:
- 用X射线结晶学来确定OsSWEET2b的结构.
- 生物化学分析以研究OsSWEET2b的运输状态和寡合化.
- OsSWEET1的结构导向突变,以确定关键的功能残留物.
主要成果:
- OsSWEET2b 形成一个不对称的结构,包括三重螺旋束和一个跨膜螺旋 (TM4).
- 观察到载体处于向内开放的 (细胞) 状态,这表明其传输机制.
- 突变性研究发现了基质转位和原体间通信的关键残留物.
结论:
- OsSWEET2b的独特结构为了解真核糖运输提供了分子基础.
- 对SWEET蛋白质结构功能关系的洞察力可以为操纵糖流的策略提供信息.
- 这项研究可能会对作物改善和植物的抗病性产生影响.
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