Hudson P J, McKern N M, Power B E, Azad A A
Nucleic Acids Res. 1986 Jun 25;14(12):5001-12. doi: 10.1093/nar/14.12.5001.
The larger RNA segment of infectious bursal disease virus (IBDV: Australian strain 002-73) has been characterized by cDNA cloning and nucleotide sequence analysis. We believe IBDV is the first birnavirus to be sequenced and so have confirmed the coding region by N-terminal amino acid sequence analysis of intact viral proteins and several tryptic peptide fragments. The large RNA segment encodes in order the 37-kDa, 28-kDa and 32-kDa proteins within a continuous open reading frame and the primary translation product appears to be subsequently processed into the mature viral proteins. The large protein precursor is still processed into the 32-kDa host protective immunogen when expressed as a fusion protein in E. coli. These results are in marked contrast to the predictions from in vitro translation data that birnavirus genomes are expressed as polycistronic templates. We can now propose that birnaviruses, in particular IBDV, possess monocistronic segments and that the precursor is proteolytically processed in vivo. The sequence data presented for the 32-kDa host protective immunogen may provide the basic information needed for the production of an effective subunit vaccine against this commercially important virus.
传染性法氏囊病病毒（IBDV：澳大利亚毒株002 - 73）的较大RNA片段已通过cDNA克隆和核苷酸序列分析进行了表征。我们认为IBDV是首个被测序的双RNA病毒，因此通过对完整病毒蛋白和几个胰蛋白酶肽片段的N端氨基酸序列分析证实了编码区。大RNA片段在一个连续的开放阅读框中依次编码37 kDa、28 kDa和32 kDa的蛋白质，初级翻译产物随后似乎被加工成成熟的病毒蛋白。当在大肠杆菌中作为融合蛋白表达时，大蛋白前体仍被加工成32 kDa的宿主保护性免疫原。这些结果与体外翻译数据的预测形成鲜明对比，体外翻译数据预测双RNA病毒基因组以多顺反子模板形式表达。我们现在可以提出，双RNA病毒，特别是IBDV，拥有单顺反子片段，并且前体在体内进行蛋白水解加工。所呈现的32 kDa宿主保护性免疫原的序列数据可能为生产针对这种具有重要商业价值的病毒的有效亚单位疫苗提供所需的基本信息。
