Three-dimensional structure of the γ-secretase complex
Three-dimensional structure of the γ-secretase complex
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DOI：
10.1016/j.bbrc.2006.02.158
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发表时间：
2006-05-05
影响因子：
3.1
通讯作者：
Sato, C
中科院分区：
文献类型：
--
作者：
Ogura, T;Mio, K;Sato, C
γ-分泌酶属于一类非典型的天冬氨酸蛋白酶，其水解底物（包括淀粉样蛋白-β前体蛋白和Notch）的跨膜结构域内的肽键。γ-分泌酶由早老素、nicastrin、APH-1和PEN-2组成，它们形成大的多聚体膜蛋白复合物，其三维结构未知。为了深入了解这种复合酶的结构，我们纯化了在Sf 9细胞中重建的功能性γ-分泌酶复合物，并使用负染电子显微镜和3D重建技术对其进行了分析。对2341个负染色颗粒图像的分析导致γ-分泌酶的三维表示，分辨率为48埃。该结构占据560 x 320 x 240埃的体积，类似于由两个相对的凹陷域组成的扁平心脏。包含多个孔的低密度空间位于域之间。在假定的跨膜区的一些凹窝可以容纳催化位点。大尺寸与γ-分泌酶活性存在于高分子量复合物内的观察结果一致。(c)2006年爱思唯尔公司All rights reserved.
gamma-Secretase belongs to an atypical class of aspartic proteases that hydrolyzes peptide bonds within the transmembrane domain of substrates, including amyloid-beta precursor protein and Notch. gamma-Secretase is comprised of presenilin, nicastrin, APH-1, and PEN-2 which form a large multimeric membrane protein complex, the three-dimensional structure of which is unknown. To gain insight into the structure of this complex enzyme, we purified functional gamma-secretase complex reconstituted in Sf9 cells and analyzed it using negative stain electron microscopy and 3D reconstruction techniques. Analysis of 2341 negatively stained particle images resulted in the three-dimensional representation of gamma-secretase at a resolution of 48 angstrom. The structure occupies a volume of 560 x 320 x 240 angstrom and resembles a flat heart comprised of two oppositely faced, dimpled domains. A low density space containing multiple pores resides between the domains. Some of the dimples in the putative transmembrane region may house the catalytic site. The large dimensions are consistent with the observation that gamma-secretase activity resides within a high molecular weight complex. (c) 2006 Elsevier Inc. All rights reserved.