RNA helicase activity of Semliki Forest virus replicase protein NSP2
RNA helicase activity of Semliki Forest virus replicase protein NSP2
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DOI：
10.1016/s0014-5793(99)00321-x
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发表时间：
1999-04-01
期刊：
影响因子：
3.5
通讯作者：
Kääriäinen, L
中科院分区：
文献类型：
--
作者：
de Cedrón, MG;Ehsani, N;Kääriäinen, L
塞姆利基森林病毒复制酶蛋白nsP2与几种推测的NTPases和RNA解旋酶具有序列同源性。NsP2具有依赖rna的NTPase活性。我们在大肠杆菌中表达了多组氨酸标记的nsP2，通过金属亲和层析纯化，并将其用于RNA解旋酶检测。以李痘痘病毒的RNA解旋酶CI为阳性对照，解绕α - p -32标记的部分双链RNA需要nsP2、Mg2+和NTPs， nsP2在与ntp结合的序列GVPGSGK(192)SA中突变K192N不能解绕dsRNA，且无NTPase活性。这是在大甲病毒超家族中首次证明RNA解旋酶活性，(C) 1999年欧洲生化学会联合会。
Semliki Forest virus replicase protein nsP2 shares sequence homology with several putative NTPases and RNA helicases. NsP2 has RNA-dependent NTPase activity. Here we expressed polyhistidine-tagged nsP2 in Escherichia coli, purified it by metal-affinity chromatography, and used it in RNA helicase assays. RNA helicase CI of plum pox potyvirus was used as a positive control, Unwinding of alpha-P-32-labelled partially double-stranded RNA required nsP2, Mg2+ and NTPs, NsP2 with a mutation, K192N, in the NTP-binding sequence GVPGSGK(192)SA could not unwind dsRNA and had no NTPase activity. This is the first demonstration of RNA helicase activity within the large alphavirus superfamily, (C) 1999 Federation of European Biochemical Societies.