Ellis M J, Knapp S, Koeck P J, Fakoor-Biniaz Z, Ladenstein R, Hebert H
Department of Biosciences, Karolinska Institutet, Huddinge, S-141 57, Sweden.
J Struct Biol. 1998 Sep;123(1):30-6. doi: 10.1006/jsbi.1998.4002.
Oligomers of the chaperonin TF55 from Sulfolobus solfataricus have been successfully crystallized in two dimensions via their interaction with a phospholipid monolayer at the air/liquid interface. Oligomer orientation was dependent upon the lipid headgroup used. A neutral lipid monolayer gave rise to small paracrystalline areas of TF55 side views, whereas a negatively charged lipid monolayer resulted in large coherent crystalline areas of the chaperonin in an end-on orientation. These 2D crystals had p312 symmetry (a = b = 162 A, gamma = 60 degrees). Two-dimensional projection structures of the end-on arrays were produced by electron microscopy and image processing techniques. Under the conditions used to grow the crystals, the protein formed complexes of two stacked nine-subunit rings with threefold symmetry.
来自嗜热栖热菌的伴侣蛋白TF55的寡聚体已通过其与气/液界面处磷脂单层的相互作用成功地在二维空间中结晶。寡聚体的取向取决于所使用的脂质头部基团。中性脂质单层产生了TF55侧视图的小准晶区域，而带负电荷的脂质单层则导致伴侣蛋白以端对端取向形成大的连贯晶体区域。这些二维晶体具有p312对称性（a = b = 162 Å，γ = 60度）。通过电子显微镜和图像处理技术获得了端对端阵列的二维投影结构。在用于生长晶体的条件下，该蛋白质形成了具有三重对称性的两个堆叠的九亚基环的复合物。
