Crystallographic structure of the α-helical triple coiled-coil domain of avian reovirus S1133 fibre
Crystallographic structure of the α-helical triple coiled-coil domain of avian reovirus S1133 fibre
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DOI：
10.1099/vir.0.008276-0
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发表时间：
2009-03-01
影响因子：
3.8
通讯作者：
van Raaij, Mark J.
中科院分区：
文献类型：
--
作者：
Guardado-Calvo, Pablo;Fox, Gavin C.;van Raaij, Mark J.
禽呼肠孤病毒纤维是sigma C蛋白的同源三聚体，是禽呼肠孤病毒外衣壳的次要组分。它通过短的N-末端序列锚定到内部衣壳λ C五聚体，并且其突出的球状C-末端结构域负责初级宿主细胞附着。我们先前已经解决了受体结合片段的结构，其中残基160-191形成三倍β螺旋，196-326形成β桶头结构域。在此，我们表达、纯化并结晶了包含残基117-326的主要sigma C片段。它的结构，这是解决了分子置换使用先前确定的受体结合域结构，并细化到1.75埃（0.175 nm）的分辨率，揭示了一个α-螺旋三重卷曲螺旋连接到先前解决的结构由含锌离子的接头。卷曲螺旋结构域包含两个氯离子结合位点，以及特定的三聚化和注册序列。接头可以充当功能上重要的铰链。
Avian reovirus fibre, a homo-trimer of the sigma C protein, is a minor component of the avian reovirus outer capsid. It is anchored via a short N-terminal sequence to the inner capsid lambda C pentamer, and its protruding globular C-terminal domain is responsible for primary host cell attachment. We have previously solved the structure of a receptor-binding fragment in which residues 160-191 form a triple beta-spiral and 196-326 a beta-barrel head domain. Here we have expressed, purified and crystallized a major sigma C fragment comprising residues 117-326. Its structure, which was solved by molecular replacement using the previously determined receptor-binding domain structure and refined to 1.75 angstrom (0.175 nm) resolution, reveals an alpha-helical triple coiled-coil connected to the previously solved structure by a zinc-ion-containing linker. The coiled-coil domain contains two chloride ion binding sites, as well as specific trimerization and registration sequences. The linker may act as a functionally important hinge.