Autoinhibition by an internal nuclear localization signal revealed by the crystal structure of mammalian importin α
Autoinhibition by an internal nuclear localization signal revealed by the crystal structure of mammalian importin α
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DOI：
10.1038/7625
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发表时间：
1999-04-01
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影响因子：
--
通讯作者：
Kobe, B
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文献类型：
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作者：
Kobe, B
Importin α是识别经典的单组分和双组分核定位信号（NLS）的核输入受体。小鼠输入素α的结构已在2.5埃分辨率下测定。该结构显示了一个大的C-末端结构域，含有犰狳重复序列，和一个结构较少的N-末端importin β-结合结构域，含有一个内部NLS结合到NLS结合位点。该结构解释了细胞质，高亲和力的形式，和核，低亲和力的形式NLS结合的核输入受体预测的当前模型的核输入之间的监管开关。可以想象，输入蛋白β通过与自身抑制序列重叠的位点结合，将低亲和力形式转化为高亲和力形式。该结构也具有理解NLS识别的含义，以及犰狳和HEAT重复序列的结构。
Importin alpha is the nuclear import receptor that recognizes classical monopartite and bipartite nuclear localization signals (NLSs). The structure of mouse importin alpha has been determined at 2.5 Angstrom resolution. The structure shows a large C-terminal domain containing armadillo repeats, and a less structured N-terminal importin beta-binding domain containing an internal NLS bound to the NLS-binding site. The structure explains the regulatory switch between the cytoplasmic, high-affinity form, and the nuclear, low-affinity form for NLS binding of the nuclear import receptor predicted by the current models of nuclear import. Importin beta conceivably converts the low- to high-affinity form by binding to a site overlapping the autoinhibitory sequence. The structure also has implications for understanding NLS recognition, and the structures of armadillo and HEAT repeats.