ホモトリメリック複合体におけるSWEETトランスポーターの構造
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
まとめ
ライス OsSWEET2bは,真空のグルコーストランスポーターで,独特のトリプルヘリックスバンドル構造を持つトリマーを形成します. この構造は,糖の輸送メカニズムと,真核生物における糖の流れの設計における潜在的な応用に関する洞察を明らかにする.
科学分野:
- 生物化学
- 分子生物学
- 植物学
背景:
- ユカリオットは,MFS,SSF,SWEETという 3つのスーパーファミリーのタンパク質を用いて糖質を輸送する.
- 植物のSWEETは糖分移転に不可欠で,花蜜の分泌,花の負荷,花粉,種子の発達に影響を与えます.
- 植物SWEETは,糖の漏れを通して病原体の感受性に影響を与える.
研究 の 目的:
- 米の真空グルコーストランスポーター OsSWEET2bの構造と機能を明らかにする.
- SWEET タンパク質による糖質転移の分子機構を理解する.
- 設計された砂糖の流れの潜在的目標を特定する.
主な方法:
- OsSWEET2bの構造を決定するX線結晶学
- OsSWEET2bの輸送状態とオリゴメリゼーションを研究するための生化学分析
- OsSWEET1の構造誘導型変異により,重要な機能的残基を特定する.
主要な成果:
- OsSWEET2bは,トリプルヘリックスバンドルとトランスメブランヘリックス (TM4) を含む非対称な構造を持つホモマートリマーを形成する.
- トランスポーターは内側に開いた状態 (サイトゾール状態) で観測され,その輸送メカニズムを示した.
- ミュタゲネーシス研究では,基板転位とプロトメア間の伝達のための重要な残留物が見つかりました.
結論:
- OsSWEET2bのユニークな構造は,真核糖の輸送を理解するための分子基盤を提供します.
- SWEET タンパク質の構造と機能の関係に関する洞察は,砂糖の流れを操作するための戦略を伝えることができます.
- この研究は作物の改善と 植物における病原性に影響を及ぼす可能性があります
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