Sample J, Lancz G, Nonoyama M
J Virol. 1986 Jan;57(1):145-54. doi: 10.1128/JVI.57.1.145-154.1986.
We used nuclease digestion to map RNA transcripts encoded in the BamHI M fragment of the Epstein-Barr virus (EBV) genome (strain B95-8). Of the five RNAs, three are rightwardly transcribed, have different cap sites but common 3' termini, and are unspliced. The two remaining RNAs are leftwardly transcribed and are 5' and 3' coterminal. One of these transcripts is spliced, resulting in the removal of a small intron from the 5' region of this RNA. We have previously published data which indicated that the BamHI M region is the first actively transcribed region of the viral genome during the replicative cycle, suggesting that one or more genes in this region is important in the initiation of EBV replication. We have now mapped two large EcoRI restriction fragments which span approximately 75% of the P3HR-1 defective genome and which contain DNA from the BamHI M region of the standard genome. The data indicate that only the coding and 5' flanking sequences for the leftwardly transcribed RNAs are intact within the defective genome. Fewer than 500 bases coding for the 3'-most regions of the rightwardly transcribed RNAs are intact, and it is unlikely that these encode functional native polypeptides. Therefore, it seems that transcriptional activation of the BamHI M-region genes is not mediated directly by the rearrangement of M genes in defective P3HR-1 EBV.
我们利用核酸酶消化法来定位编码在爱泼斯坦-巴尔病毒（EBV，B95-8株）基因组的BamHI M片段中的RNA转录本。在这5种RNA中，3种是向右转录的，具有不同的帽位点但共有3'末端，且未经过剪接。其余2种RNA是向左转录的，5'和3'末端相同。其中一种转录本经过剪接，导致该RNA 5'区域的一个小内含子被去除。我们之前发表的数据表明，BamHI M区域是病毒基因组在复制周期中第一个活跃转录的区域，这表明该区域中的一个或多个基因在EBV复制起始过程中很重要。我们现在定位了两个大的EcoRI限制片段，它们覆盖了约75%的P3HR-1缺陷基因组，并且包含来自标准基因组BamHI M区域的DNA。数据表明，在缺陷基因组中，只有向左转录的RNA的编码序列和5'侧翼序列是完整的。向右转录的RNA 3'最末端区域的编码碱基少于500个，而且这些碱基不太可能编码有功能的天然多肽。因此，似乎BamHI M区域基因的转录激活不是由缺陷型P3HR-1 EBV中M基因的重排直接介导的。
