Lamb R A, Choppin P W, Chanock R M, Lai C J
Proc Natl Acad Sci U S A. 1980 Apr;77(4):1857-61. doi: 10.1073/pnas.77.4.1857.
RNA segment 8 of the influenza virus genome is unique in coding for two polypeptides, NS1 (Mr, approximately 25,000) and NS2 (Mr, approximately 11,000). These polypeptides are synthesized from separate mRNA species. By using cloned DNA derived from RNA segment 8 (NS DNA) the two mRNAs have been mapped on segment 8 by hybridization of mRNAs with restriction endonuclease fragments of the DNA and nuclease S1 digestion methods. These data indicate that the body of the NS1 mRNA (approximately 850 nucleotides) maps at 0.05-0.95 units of the cloned NS DNA and the body of the NS2 mRNA (approximately 340 nucleotides) maps at 0.59-0.95 unitssuggesting that the two mRNAs are 3' coterminal and share the same poly(A) addition site. These positions of the mRNAs on the viral genome segment were confirmed in hybrid-arrested translation experiments using fragments of the cloned NS DNA to inhibit the synthesis in vitro of NS1 or NS2 polypeptides. In addition, in these translation experiments the use of certain DNA fragments resulted in premature termination of the NS1 polypeptide. From these data, it could be estimated that the termination of translation of NS1 is at approximately 0.76 map unit. Thus, the coding regions of the two mRNAs overlap by approximately 144-159 nucleotides, the equivalent of approximately 48-53 amino acids. Peptide mapping experiments indicated that polypeptides NS1 and NS2 do not share methionine- or leucine-containing tryptic peptides. The results obtained indicate the translation of the NS2 mRNA occurs in a reading frame different from that used for NS1.
流感病毒基因组的RNA片段8在编码两种多肽NS1（分子量约25,000）和NS2（分子量约11,000）方面独具特色。这些多肽由不同的mRNA种类合成。通过使用源自RNA片段8的克隆DNA（NS DNA），利用mRNA与DNA的限制性内切酶片段杂交以及核酸酶S1消化方法，已将这两种mRNA定位在片段8上。这些数据表明，NS1 mRNA的主体（约850个核苷酸）位于克隆NS DNA的0.05 - 0.95单位处，而NS2 mRNA的主体（约340个核苷酸）位于0.59 - 0.95单位处，这表明这两种mRNA是3' 共末端的，并且共享相同的聚腺苷酸添加位点。在使用克隆NS DNA片段抑制NS1或NS2多肽体外合成的杂交阻断翻译实验中，证实了这些mRNA在病毒基因组片段上的位置。此外，在这些翻译实验中，使用某些DNA片段会导致NS1多肽提前终止。根据这些数据，可以估计NS1翻译的终止位置约在0.76图单位处。因此，两种mRNA的编码区域重叠约144 - 159个核苷酸，相当于约48 - 53个氨基酸。肽图谱实验表明，多肽NS1和NS2不共享含甲硫氨酸或亮氨酸的胰蛋白酶肽段。所得结果表明，NS2 mRNA的翻译发生在与NS1不同的阅读框中。
