Loesch W T, Arlinghaus A
Arch Virol. 1975;47(3):201-15. doi: 10.1007/BF01317808.
One host polypeptide (40,000 daltons) synthesized prior to infection is associated with the 250S RNA polymerase structure partially purified by a combination of velocity sedimentation and isopycnic separation. A series of pulse-chase experiments have shown that a 56,000 dalton polypeptide made during the eclipse phase of infection is inserted into the 250S viral RNA polymerase structure. This 56,000 dalton polypeptide is bound in a stable manner since labeled 56,000 dalton polypeptide is not removed from the 250S polymerase structure by a 2-hour chase (3 to 5 hours after infection) and it is the major labeled polypeptide species remaining. However, the 56,000 dalton polypeptide (viral-specific polypeptide E) made at 4 hours after infection is not present in the 250S polymerase structure following a 50 minue chase. Levels of cycloheximide which inhibit protein synthesis 95 per cent in the infected cell have no effect on the amount of viral-specific RNA polymerase activity (in vitro) when the inhibitor is added for 30 minutes at the time of maximum rate of viral RNA synthesis in whole cells. These inhibitor studies support the hypothesis that the viral-specific RNA polymerase polypeptide may be a stable polypeptide that is not rapidly turning over in the infected cell. In view of these results the stable 56,000 dalton polypeptide (polypeptide E) made early in infection may be a candidate for the viral-specific polymerase polypeptide.
一种在感染前合成的宿主多肽（40,000道尔顿）与通过速度沉降和等密度分离相结合的方法部分纯化的250S RNA聚合酶结构相关。一系列脉冲追踪实验表明，在感染的隐蔽期产生的一种56,000道尔顿的多肽被插入到250S病毒RNA聚合酶结构中。这种56,000道尔顿的多肽以稳定的方式结合，因为标记的56,000道尔顿多肽在2小时的追踪（感染后3至5小时）后不会从250S聚合酶结构中去除，并且它是剩余的主要标记多肽种类。然而，感染后4小时产生的56,000道尔顿多肽（病毒特异性多肽E）在50分钟的追踪后不存在于250S聚合酶结构中。当在全细胞中病毒RNA合成的最大速率时添加抑制剂30分钟时，抑制感染细胞中95%蛋白质合成的环己酰亚胺水平对病毒特异性RNA聚合酶活性（体外）的量没有影响。这些抑制剂研究支持了这样的假设，即病毒特异性RNA聚合酶多肽可能是一种稳定的多肽，在感染细胞中不会快速周转。鉴于这些结果，感染早期产生的稳定的56,000道尔顿多肽（多肽E）可能是病毒特异性聚合酶多肽的候选者。
