Structural and Functional Characterization of the Mumps Virus Phosphoprotein
Structural and Functional Characterization of the Mumps Virus Phosphoprotein
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DOI：
10.1128/jvi.00653-13
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发表时间：
2013-07-01
影响因子：
5.4
通讯作者：
Luo, Ming
中科院分区：
文献类型：
--
作者：
Cox, Robert;Green, Todd J.;Luo, Ming
磷蛋白（P）由弹状病毒科（Rhabdoviridae）和副粘病毒科（Paramyxoviridae）在单负病毒目（Mononegavirales）中病毒编码。P是一种自缔合寡聚体，与大病毒聚合酶蛋白（L）、核衣壳蛋白（N）和组装的核衣壳形成复合物。来自不同病毒的P虽然基本功能相同，但结构上却存在差异。我们系统地绘制了腮腺炎病毒（MuV）P的结构域，并研究了它们与核衣壳样颗粒（NLP）的相互作用。与其他P蛋白类似，MuV P包含N-末端、中心和C-末端结构域，相邻结构域之间具有柔性接头。通过pulldown分析，我们发现除了先前提出的核衣壳结合结构域（残基343至391），MuVP的N-末端区域（残基1至194）也可以结合NLP。使用表面等离子体共振进行结合动力学的进一步分析。这是第一次观察到负链RNA病毒P的N-和C-末端区域都参与结合核衣壳。此外，我们还确定了MuVP的寡聚化结构域（P-OD）为213 - 277位残基，并测定了其晶体结构。四聚MuV P-OD由一对长的平行α-螺旋与另一对相反取向的α-螺旋形成。与仙台病毒P-OD四聚体中每个α-螺旋的平行取向不同，这代表了P-OD的一种新取向，其中N-和C-末端结构域都位于四聚体的任一末端。这与N-和C-末端结构域都参与结合核衣壳的观察结果一致。
The phosphoprotein (P) is virally encoded by the Rhabdoviridae and Paramyxoviridae in the order Mononegavirales. P is a selfassociated oligomer and forms complexes with the large viral polymerase protein (L), the nucleocapsid protein (N), and the assembled nucleocapsid. P from different viruses has shown structural diversities even though their essential functions are the same. We systematically mapped the domains in mumps virus (MuV) P and investigated their interactions with nucleocapsidlike particles (NLPs). Similar to other P proteins, MuV P contains N-terminal, central, and C-terminal domains with flexible linkers between neighboring domains. By pulldown assays, we discovered that in addition to the previously proposed nucleocapsid binding domain (residues 343 to 391), the N-terminal region of MuV P (residues 1 to 194) could also bind NLPs. Further analysis of binding kinetics was conducted using surface plasmon resonance. This is the first observation that both the N-and C-terminal regions of a negative-strand RNA virus P are involved in binding the nucleocapsid. In addition, we defined the oligomerization domain (P-OD) of MuV P as residues 213 to 277 and determined its crystal structure. The tetrameric MuV P-OD is formed by one pair of long parallel alpha-helices with another pair in opposite orientation. Unlike the parallel orientation of each alpha-helix in the tetramer of Sendai virus P-OD, this represents a novel orientation of a P-OD where both the N-and the C-terminal domains are at either end of the tetramer. This is consistent with the observation that both the N-and the C-terminal domains are involved in binding the nucleocapsid.