Mavrakis Manos, Kolesnikova Larissa, Schoehn Guy, Becker Stephan, Ruigrok Rob W H
EMBL Grenoble Outstation, Grenoble Cedex 9, France.
Virology. 2002 May 10;296(2):300-7. doi: 10.1006/viro.2002.1433.
When Marburg virus (MBGV) nucleoprotein (NP) is expressed in insect cells, it binds to cellular RNA and forms NP-RNA complexes such as insect cell-expressed nucleoproteins from other nonsegmented negative-strand RNA viruses. Recombinant MBGV NP-RNA forms loose coils that resemble rabies virus N-RNA. MBGV NP monomers are rods that are spaced along the coil similar to the nucleoprotein monomers of the rabies virus N-RNA. High salt treatment induces tight coiling of the MBGV NP-RNA, again a characteristic observed for other nonsegmented negative-strand virus N-RNAs. Electron microscopy of fixed Marburg virus particles shows that the viral nucleocapsid has a smaller diameter than the free, recombinant NP-RNA. This difference in helical parameters could be caused by the interaction of other viral proteins with the NP-RNA. A similar but opposite phenomenon is observed for rhabdovirus nucleocapsids that are condensed by the viral matrix protein upon which they acquire a larger diameter. Finally, there appears to be an extensive and regular protein scaffold between the viral nucleocapsid and the membrane that seems not to exist in the other negative-strand RNA viruses.
当马尔堡病毒（MBGV）核蛋白（NP）在昆虫细胞中表达时，它会与细胞RNA结合并形成NP-RNA复合物，就像其他非节段性负链RNA病毒在昆虫细胞中表达的核蛋白一样。重组MBGV NP-RNA形成类似于狂犬病病毒N-RNA的松散螺旋。MBGV NP单体呈杆状，沿螺旋排列，类似于狂犬病病毒N-RNA的核蛋白单体。高盐处理会导致MBGV NP-RNA紧密盘绕，这也是其他非节段性负链病毒N-RNA所具有的特征。对固定的马尔堡病毒颗粒进行电子显微镜观察显示，病毒核衣壳的直径比游离的重组NP-RNA小。螺旋参数的这种差异可能是由其他病毒蛋白与NP-RNA的相互作用引起的。对于弹状病毒核衣壳，观察到一种类似但相反的现象，即病毒基质蛋白会使其浓缩，从而使其直径变大。最后，在病毒核衣壳和膜之间似乎存在一个广泛且规则的蛋白质支架，而其他负链RNA病毒中似乎不存在这种支架。
