SPECIFIC RNA FRAGMENTS IN DEFECTIVE PARTICLES OF BACTERIOPHAGE-MS2
SPECIFIC RNA FRAGMENTS IN DEFECTIVE PARTICLES OF BACTERIOPHAGE-MS2
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DOI：
10.1016/0014-5793(74)81112-9
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发表时间：
1974-01-01
期刊：
影响因子：
3.5
通讯作者：
GREN, EJ
中科院分区：
文献类型：
--
作者：
RENHOF, RF;VESELOVA, SV;GREN, EJ
含RNA噬菌体的A蛋白的琥珀突变体在限制性生长条件下形成缺陷噬菌体颗粒[1]。在野生型RNA噬菌体中也观察到不同类型的缺陷颗粒[2]，包括在正常条件下繁殖的那些[3]。在这篇通讯中，已经表明在E.大肠杆菌AB 259宿主细胞在蛋白胨和合成培养基中都是有缺陷的。缺陷病毒体与天然噬菌体的不同之处在于它们的浮力密度较低，感染性可忽略不计，并且主要含有片段化的RNA。然而，RNA：蛋白质和A-蛋白质：外壳蛋白的比例在缺陷和天然MS 2颗粒是大致相同的。缺陷颗粒中所含的RNA主要由三个特异性片段组成，它们的长度约为天然MS 2 RNA长度的60%、50%和40%，这显然是由缺陷噬菌体颗粒中所含的天然RNA分子中的几个断裂造成的。主要破裂发生在3 '。MS 2 RNA的末端一半导致短3 '的形成。终端和长5 '。末端片段占整个RNA长度的40%和60%。
Amber mutants of A-protein of RNA-containing bacteriophages form defective phage particles under restrictive conditions of growth [l]. Different types of defective particles have been also observed among wild type RNA bacteriophages [2] including those multiplying under normal conditions [3]. In this communication it has been shown that some of the bacteriophage MS2 virions grown in E. coli AB 259 host cells both in the peptone and synthetic media are defective. Defective virions differ from the native phage by their lower buoyant density, negligible infectivity and as mainly containing fragmented RNA. However, RNA: protein and A-protein: coat protein ratios in the defective and native MS2 particles are approximately the same. RNA contained in the defective particles is composed mainly of three specific fragments, their length being about 60, 50 and 40% of that of the native MS2 RNA, what obviously results from several ruptures in the native RNA molecule included in defective phage particles. The major rupture occurring in the 3’. terminal half of MS2 RNA leads to the formation of short 3’. terminal and long 5’. terminal fragments with 40 and 60% of the whole RNA length.