Influenza virion transcriptase: synthesis in vitro of large, polyadenylic acid-containing complementary RNA
Influenza virion transcriptase: synthesis in vitro of large, polyadenylic acid-containing complementary RNA
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流感病毒体转录酶：含聚腺苷酸的大互补 RNA 的体外合成
DOI：
10.1128/jvi.21.1.24-34.1977
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发表时间：
1977
影响因子：
5.4
通讯作者：
R. Krug
中科院分区：
文献类型：
--
作者：
S. Plotch;R. Krug
流感病毒体转录酶能够在体外合成互补RNA (cRNA)，其在几个特征上与受感染细胞中合成的cRNA（即病毒mRNA）相似。大多数体外 cRNA 较大（大约 2.5 X 10(5) 至 10(6) 道尔顿），与体内 cRNA 大小相似。体外转录起始于 5' 端的腺苷 (A) 或鸟苷 (G)，体内 cRNA 的情况似乎也是如此（R.M. Krug 等人，1976）。体外转录物包含共价连接的聚腺苷酸 [poly(A)] 序列，该序列比体内 cRNA 上发现的 Poly(A) 序列更长且更异质。具有这些特性的 cRNA 的体外合成需要适当的二价阳离子 Mg2+ 和特定的二核糖苷单磷酸噬菌体 (DNMP)、ApG 或 GpG。这些 DNMP 在 Mg2+ 存在下刺激 cRNA 合成约 100 倍，并充当启动 RNA 链的引物，这些 DNMP 的 5'-磷酸化衍生物 32pApG 或 32pGpG 被掺入到产物 RNA 的 5' 端这一事实证明了这一点。体外合成的 RNA 与体内 cRNA 的不同之处在于，体外转录本未检测到加帽或甲基化。病毒体确实含有甲基化酶活性，如其甲基化外源甲基缺陷型大肠杆菌 tRNA 的能力所示。
The influenza virion transcriptase is capable of synthesizing in vitro complementary RNA (cRNA) that is similar in several characteristics to the cRNA synthesized in the infected cell, which is the viral mRNA. Most of the in vitro cRNA is large (approximately 2.5 X 10(5) to 10(6) daltons), similar in size to in vivo cRNA. The in vitro transcripts initiate in adenosine (A) or guanosine (G) at the 5' end, as also appears to be the case with in vivo cRNA (R.M. Krug et al., 1976). The in vitro transcripts contain covalently linked polyadenylate [poly(A)] sequences, which are longer and more heterogeneous than the poly(A) sequences found on in vivo cRNA. The synthesis in vitro of cRNA with these characteristics requires both the proper divalent cation, Mg2+, and a specific dinulceside monophosphage (DNMP), ApG or GpG. These DNMPs stimulate cRNA synthesis about 100-fold in the presence of Mg2+ and act as primers to initiate RNA chains, as demonstrated by the fact that the 5'-phosphorylated derivatives of these DNMP's, 32pApG or 32pGpG, are incroporated at the 5' end of the product RNA. The RNA synthesized in vitro differs from in vivo cRNA in that neither capping nor methylation of the in vitro transcripts has been detected. The virion does contain a methylase activity, as shown by its ability to methylate exogenous methyl-deficient Escherichia coli tRNA.