Crystal structure and biophysical properties of a complex between the N-terminal SNARE region of SNAP25 and syntaxin 1a.
Crystal structure and biophysical properties of a complex between the N-terminal SNARE region of SNAP25 and syntaxin 1a.
复制标题
DOI：
10.1074/jbc.m106853200
复制
发表时间：
2001-11-02
影响因子：
4.8
通讯作者：
Weis, WI
中科院分区：
文献类型：
--
作者：
Misura, KMS;Gonzalez, LC;Weis, WI
SNARE蛋白是细胞膜内融合所必需的。在神经元中，质膜SNARES syntaxin 1a和SNAP25与在神经递质囊泡上发现的VAMP2结合。这三种蛋白质含有“SNARE区域”，介导它们结合成稳定的四聚体卷曲线圈结构。Syntaxin la提供一个这样的区域，称为H3， SNAP25为与VAMP2的融合复合体提供两个SNARE区域。Syntaxin laH3 （synlaH3）和SNAP25可以形成一个稳定的组装体，然后可以通过VAMP2结合形成完整的SNARE复合物。在这里，我们发现syn1aH3也可以与SNAP25 （S25N）的n端SNARE区形成稳定但被动力学捕获的配合物。该复合物的晶体结构显示了一个延伸的平行四螺旋束，类似于核心SNARE和syn1aH3的结构。SNAP25复合物。synlaH3和S25N在体外稳定结合的固有能力表明，细胞内融合机制必须防止形成或去除任何非生产复合物。与syn1aH3（.）的比较SNAP25复合物表明，N端和c端SNAP25 SNARE区域的连接在防止非生产性syn1aH3的形成方面具有动力学优势（）。S25N复杂。我们还证明了syn1aH3（.）S25N配合物可被a-SNAP和n -乙基马来酰亚胺敏感因子分解。
SNARE proteins are required for intracellular membrane fusion. In the neuron, the plasma membrane SNARES syntaxin 1a and SNAP25 bind to VAMP2 found on neurotransmitter-containing vesicles. These three proteins contain "SNARE regions" that mediate their association into stable tetrameric coiled-coil structures. Syntaxin la contributes one such region, designated H3, and SNAP25 contributes two SNARE regions to the fusogenic complex with VAMP2. Syntaxin la H3 (synlaH3) and SNAP25 can form a stable assembly, which can then be bound by VAMP2 to form the full SNARE complex. Here we show that syn1aH3 can also form a stable but kinetically trapped complex with the N-terminal SNARE region of SNAP25 (S25N). The crystal structure of this complex reveals an extended parallel four-helix bundle similar to that of the core SNARE and the syn1aH3(.)SNAP25 complexes. The inherent ability of synlaH3 and S25N to associate stably in vitro implies that the intracellular fusion machinery must prevent formation of, or remove, any nonproductive complexes. Comparison with the syn1aH3(.)SNAP25 complex suggests that the linkage of the N- and C-terminal SNAP25 SNARE regions is kinetically advantageous in preventing formation of the non-productive syn1aH3(.)S25N complex. We also demonstrate that the syn1aH3(.)S25N complex can be disassembled by a-SNAP and N-ethylmaleimide-sensitive factor.