Fan Shilong, Feng Yingang, Wei Zhiyi, Xia Bin, Gong Weimin
School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Protein Pept Lett. 2009;16(2):189-95. doi: 10.2174/092986609787316342.
Synbindin is one component of Transport protein particle (TRAPP) complexes. In the hippocampal neurons, synbindin binds syndecan-2 by its atypical PDZ domain (APD) and may regulate the formation of dendritic spines. To investigate the interaction of synbindin and syndecan-2, we determined the solution structure of the synbindin APD by NMR. The structure of APD is different from the classical canonical PDZ domains by lacking the typical alphaA helix and the signature sequence Gly-Psi-Gly-Psi. These differences indicate that APD may not bind syndecan-2 with the typical binding mode of other PDZ domain proteins. In NMR titration experiments, APD do not bind with the C-terminal TKEFYA peptide of syndecan-2, but can interact with the 32-residue cytoplasmic domain of syndecan-2 very weakly.
突触结合蛋白是转运蛋白颗粒（TRAPP）复合物的一个组成部分。在海马神经元中，突触结合蛋白通过其非典型PDZ结构域（APD）与syndecan-2结合，并可能调节树突棘的形成。为了研究突触结合蛋白与syndecan-2的相互作用，我们通过核磁共振（NMR）确定了突触结合蛋白APD的溶液结构。APD的结构与经典的标准PDZ结构域不同，它缺少典型的αA螺旋和特征序列Gly-Psi-Gly-Psi。这些差异表明，APD可能不会以其他PDZ结构域蛋白的典型结合模式与syndecan-2结合。在核磁共振滴定实验中，APD不与syndecan-2的C末端TKEFYA肽结合，但能与syndecan-2的32个残基的胞质结构域非常微弱地相互作用。
