Cologna R, Hogue B G
Division of Molecular Virology, Houston, Texas, USA.
Adv Exp Med Biol. 1998;440:355-9.
The coronavirus nucleocapsid protein (N) is involved in encapsidation and packaging of viral RNA. In this study we investigated the ability of the bovine coronavirus (BCV) N protein to interact with RNA. Histidine-tagged BCV N (his-N) protein was expressed in bacteria. A filter binding assay was established to quantitatively measure the binding efficiency of purified his-N to different RNAs. The results indicate that bacterially expressed N bound both BCV and mouse hepatitis coronavirus (MHV) RNAs. Binding to in vitro generated BCV and MHV RNA transcripts was significantly higher than binding to a non-coronavirus RNA. Similar binding efficiencies were measured for a BCV defective genome, pDrep, and a transcript that contained the MHV packaging signal. Interestingly, the entire MHV DI, pMIDI-C, was bound at a higher efficiency than the packaging signal alone. This is one of the first reports to show that N interacts with the MHV packaging signal.
冠状病毒核衣壳蛋白（N）参与病毒RNA的衣壳化和包装。在本研究中，我们调查了牛冠状病毒（BCV）N蛋白与RNA相互作用的能力。带有组氨酸标签的BCV N（his-N）蛋白在细菌中表达。建立了一种滤膜结合测定法来定量测量纯化的his-N与不同RNA的结合效率。结果表明，细菌表达的N与BCV和小鼠肝炎冠状病毒（MHV）的RNA均有结合。与体外生成的BCV和MHV RNA转录本的结合明显高于与非冠状病毒RNA的结合。对于BCV缺陷基因组pDrep和包含MHV包装信号的转录本，测得的结合效率相似。有趣的是，整个MHV DI（pMIDI-C）的结合效率高于单独的包装信号。这是首批表明N与MHV包装信号相互作用的报告之一。
