Wang L H, Duesberg P H
J Virol. 1973 Dec;12(6):1512-21. doi: 10.1128/JVI.12.6.1512-1521.1973.
Kirsten murine sarcoma-leukemia virus (Ki-MSV[MLV]) was found to contain less RNase H per unit of viral DNA polymerase than avian Rous sarcoma virus (RSV). Upon purification by chromatography on Sephadex G-200 and subsequent glycerol gradient sedimentation the avian DNA polymerase was obtained in association with a constant amount of RNase H. By contrast, equally purified DNA polymerase of Ki-MSV(MLV) and Moloney [Mo-MSV(MLV)] lacked detectable RNase H if assayed with two homopolymer and phage fd DNA-RNA hybrids as substrates. On the basis of picomoles of nucleotides turned over, the ratio of RNase H to purified avian DNA polymerase was 1:20 and that of RNase H to purified murine DNA polymerase ranged between <1:2,800 and 5,000. Based on the same activity with poly (A).oligo(dT) the activity of the murine DNA polymerase was 6 to 60 times lower than that of the avian enzyme with denatured salmon DNA template or with avian or murine viral RNA templates assayed under various conditions (native, heat-dissociated, with or without oligo(dT) and oligo(dC) and at different template enzyme ratios). The template activities of Ki-MSV(MLV) RNA and RSV RNA were enhanced uniformly by oligo(dT) but oligo(dC) was much less efficient in enhancing the activity of MSV(MLV) RNA than that of RSV RNA. It was concluded that the purified DNA polymerase of Ki-MSV(MLV) differs from that of Rous sarcoma virus in its lack of detectable RNase H and in its low capacity to transcribe viral RNA and denatured salmon DNA. Some aspects of these results are discussed.
发现 Kirsten 小鼠肉瘤白血病病毒（Ki-MSV[MLV]）每单位病毒 DNA 聚合酶所含的核糖核酸酶 H（RNase H）比禽 Rous 肉瘤病毒（RSV）少。通过在 Sephadex G - 200 上进行层析纯化以及随后的甘油梯度沉降，禽 DNA 聚合酶与恒定数量的 RNase H 结合获得。相比之下，若以两种均聚物和噬菌体 fd DNA - RNA 杂交体为底物进行检测，经同样纯化的 Ki-MSV(MLV)和 Moloney [Mo-MSV(MLV)]的 DNA 聚合酶未检测到 RNase H。以翻转的核苷酸皮摩尔数为基础，RNase H 与纯化的禽 DNA 聚合酶的比例为 1:20，而 RNase H 与纯化的小鼠 DNA 聚合酶的比例在<1:2800 至 5000 之间。基于对聚（A）·寡聚（dT）的相同活性，在各种条件下（天然、热解离、有无寡聚（dT）和寡聚（dC）以及不同的模板 - 酶比例），以变性鲑鱼 DNA 模板或禽或小鼠病毒 RNA 模板检测时，小鼠 DNA 聚合酶的活性比禽酶低 6 至 60 倍。Ki-MSV(MLV) RNA 和 RSV RNA 的模板活性均被寡聚（dT）均匀增强，但寡聚（dC）增强 MSV(MLV) RNA 活性的效率远低于增强 RSV RNA 活性的效率。得出的结论是，纯化的 Ki-MSV(MLV) DNA 聚合酶与 Rous 肉瘤病毒的 DNA 聚合酶不同，其缺乏可检测到的 RNase H，且转录病毒 RNA 和变性鲑鱼 DNA 的能力较低。讨论了这些结果的某些方面。
