Cryo-EM structure of SNAP-SNARE assembly in 20S particle
Cryo-EM structure of SNAP-SNARE assembly in 20S particle
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DOI：
10.1038/cr.2015.47
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发表时间：
2015-04
期刊：
影响因子：
44.1
通讯作者：
Qiang Zhou;Xuan Huang;Sha Sun;Xueming Li;Hongwei Wang;Sen‐fang Sui
中科院分区：
文献类型：
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作者：
Qiang Zhou;Xuan Huang;Sha Sun;Xueming Li;Hongwei Wang;Sen‐fang Sui
N-乙基马来酰亚胺敏感因子(N-乙基马来酰亚胺敏感因子)和α可溶性的N-乙基马来酰亚胺结合蛋白(α-SNAPs)在20s的颗粒内共同作用，在细胞膜融合后分解和回收SNAP受体(SNARE)复合体。为了了解SNARE复合体被NSF和α-SNAP拆解的机理，我们对20S颗粒进行了单颗粒冷冻电子显微镜分析，并在7.35A的分辨率下确定了α-SNAP-SNARE组装部分的结构。该结构表明，四个α-Snap将单个左手SNARE螺旋束作为一个右手圆柱组件缠绕在一个20s的粒子内。一个保守的疏水补丁连接每个α-SNAP的螺旋9和10，形成一个突出到SNARE四螺旋束的沟槽中的阻塞。生化研究证明，这种结构元件对SNARE复合体的分解至关重要。我们的研究表明，四个α-Snap可能与国家科学基金协调，将SNARE复合体撕裂成单独的蛋白质。
N-ethylmaleimide-sensitive factor (NSF) and α soluble NSF attachment proteins (α-SNAPs) work together within a 20S particle to disassemble and recycle the SNAP receptor (SNARE) complex after intracellular membrane fusion. To understand the disassembly mechanism of the SNARE complex by NSF and α-SNAP, we performed single-particle cryo-electron microscopy analysis of 20S particles and determined the structure of the α-SNAP-SNARE assembly portion at a resolution of 7.35 Å. The structure illustrates that four α-SNAPs wrap around the single left-handed SNARE helical bundle as a right-handed cylindrical assembly within a 20S particle. A conserved hydrophobic patch connecting helices 9 and 10 of each α-SNAP forms a chock protruding into the groove of the SNARE four-helix bundle. Biochemical studies proved that this structural element was critical for SNARE complex disassembly. Our study suggests how four α-SNAPs may coordinate with the NSF to tear the SNARE complex into individual proteins.