Avota E, Berzins V, Grens E, Vishnevsky Y, Luce R, Biebricher C K
Biomedical Research and Study Center, Riga, Latvia.
J Mol Biol. 1998 Feb 13;276(1):7-17. doi: 10.1006/jmbi.1997.1496.
The RNA of Escherichia coli infected with RNA bacteriophage Q beta was isolated and screened for replicable short-chained RNA. In contrast to earlier assumptions we show that (i) short-chained replicable RNA is a very minor part of the RNA synthesized in the infection cycle, and (ii) that the replicable RNA isolated from infected cells is derived from cellular RNA, in particular 23 S rRNA and 10 Sa RNA, and from Q beta RNA itself. None of the many RNA species known from in vitro experiments was found. The RNA species isolated were all inefficient templates. No replicable RNA could be isolated from non-infected cells. Even in cells expressing high amounts of Q beta replicase very few RNA species could be isolated. RNA generated in vitro in template-free synthesis is therefore not derived from RNA species found in vivo, and replicable RNA found in vitro is generated by a mechanism fundamentally different from the one operating in vivo.
分离出感染了RNA噬菌体Qβ的大肠杆菌的RNA，并筛选可复制的短链RNA。与早期的假设相反，我们发现：（i）短链可复制RNA在感染周期中合成的RNA中只占很小一部分；（ii）从感染细胞中分离出的可复制RNA来源于细胞RNA，特别是23S rRNA和10Sa RNA，以及Qβ RNA本身。未发现体外实验中已知的众多RNA种类中的任何一种。分离出的RNA种类都是低效模板。未从未感染细胞中分离出可复制RNA。即使在大量表达Qβ复制酶的细胞中，也只能分离出极少数RNA种类。因此，体外无模板合成产生的RNA并非来源于体内发现的RNA种类，体外发现的可复制RNA是由一种与体内运作机制根本不同的机制产生的。
