Suzuki Kaoru, Adachi Wataru, Yamada Noriyo, Tsunoda Masaru, Koike Kichiko, Koike Masahiko, Sekiguchi Takeshi, Takénaka Akio
Department of Environmental Science, College of Science and Engineering, Iwaki Meisei University, Chuodai-iino, Iwaki 970-8551, Japan.
Acta Crystallogr D Biol Crystallogr. 2002 May;58(Pt 5):833-5. doi: 10.1107/s0907444902005048. Epub 2002 Apr 26.
The full-length (untruncated) dihydrolipoamide succinyltransferase from pig heart was crystallized by the hanging-drop vapour-diffusion method. X-ray diffraction patterns indicate that the crystal belongs to space group I432, with unit-cell parameter a = 189.9 A. The crystal structure has been preliminarily solved at 7 A resolution by the molecular-replacement method. The unit cell contains two cubic cores, in each of which 24 subunits of E2 are associated according to crystallographic 432 symmetry. At the corners of each cubic core, the catalytic domains of E2s form a trimer through tight interactions around the crystallographic threefold axes. In the electron-density maps, many small broad peaks are observed in regions expected to contain the remaining N-terminal domains (the E1/E3-binding domain and the lipoyl domain), suggesting flexibility of these domains relative to the core. The architecture of the cubic core is similar to that of the other truncated E2s. In the unit cell, however, the core-core contact occurs in a different direction from that found for the truncated proteins.
采用悬滴气相扩散法对猪心全长（未截短）二氢硫辛酰胺琥珀酰转移酶进行了结晶。X射线衍射图谱表明，该晶体属于空间群I432，晶胞参数a = 189.9 Å。通过分子置换法在7 Å分辨率下初步解析了晶体结构。晶胞包含两个立方核心，每个核心中24个E2亚基根据晶体学432对称性缔合。在每个立方核心的角上，E2的催化结构域通过围绕晶体学三重轴的紧密相互作用形成三聚体。在电子密度图中，预计包含其余N端结构域（E1/E3结合结构域和硫辛酰结构域）的区域观察到许多小而宽的峰，表明这些结构域相对于核心具有灵活性。立方核心的结构与其他截短E2的结构相似。然而，在晶胞中，核心与核心的接触方向与截短蛋白的不同。
