Buss F, Kent H, Stewart M, Bailer S M, Hanover J A
MRC Laboratory of Molecular Biology, Cambridge, UK.
J Cell Sci. 1994 Feb;107 ( Pt 2):631-8. doi: 10.1242/jcs.107.2.631.
We have expressed rat nucleoporin p62 cDNA in Escherichia coli to obtain material for structural and self-association studies. Electron microscopy and circular dichroism spectroscopy are consistent with a rod-shaped molecule with an alpha-helical coiled-coil domain at its C terminus and a cross-beta structure at its N terminus, separated by a threonine-rich linker, which has a less-defined secondary structure. Electron microscopy and the solubility properties of fragments produced using thrombin and CNBr digestion indicate that p62 molecules associate to form linear chains and that a small region near the C terminus is an important determinant of assembly. This association may have important consequences for pore structure and function; for example, one way p62 could associate would be to form rings in nuclear pores that could function like barrel hoops.
我们已在大肠杆菌中表达大鼠核孔蛋白p62的cDNA，以获取用于结构和自缔合研究的材料。电子显微镜和圆二色光谱表明，该分子呈棒状，其C端有一个α-螺旋卷曲螺旋结构域，N端有一个交叉β结构，中间由富含苏氨酸的连接子隔开，该连接子的二级结构不太明确。电子显微镜以及使用凝血酶和溴化氰消化产生的片段的溶解性表明，p62分子缔合形成线性链，并且C端附近的一个小区域是组装的重要决定因素。这种缔合可能对孔的结构和功能有重要影响；例如，p62缔合的一种方式可能是在核孔中形成环，其功能类似于桶箍。
