Kaufmann G, Amitsur M
Nucleic Acids Res. 1985 Jun 25;13(12):4333-41. doi: 10.1093/nar/13.12.4333.
T4 mutants lacking polynucleotide kinase (pnk-) or RNA ligase (rli-) do not grow on E. coli CTr5x. During the abortive infections there accumulate host tRNA fragments that match into two species severed 3' to the anticodon. The CTr5x-specific fragments appear only transiently with wt phage, implicating the affected enzymes in phosphoryl group rearrangement and religation [David et al. (1982) Virol. 123, 480]. In a search for the vulnerable host tRNAs and putative religation products, tRNA ensembles from uninfected E. coli CTr5x or cells infected with various phage strains were fractionated and compared. A tRNA species absent from rli- infected cells but present in uninfected cells or late in wt infection was thus detected. RNase T1 finger prints of this species, isolated before or after wt infection, were compared with that of an in vitro ligated pair of CTr5x-specific fragments. The results indicated that this tRNA is cleaved upon infection and later on restored to it's original or to a very similar form, by polynucleotide kinase and RNA ligase reactions. It is suggested that depletion of such vulnerable host tRNA species underlies the restriction of pnk- or rli- phage on E. coli CTr5x.
缺乏多核苷酸激酶（pnk-）或RNA连接酶（rli-）的T4突变体不能在大肠杆菌CTr5x上生长。在流产感染期间，会积累与反密码子3'端切割成两种类型相匹配的宿主tRNA片段。CTr5x特异性片段仅在野生型噬菌体感染时短暂出现，这表明受影响的酶参与磷酸基团重排和重新连接反应[David等人（1982年），《病毒学》123卷，480页]。为了寻找易受影响的宿主tRNA和假定的重新连接产物，对未感染的大肠杆菌CTr5x或感染各种噬菌体菌株的细胞中的tRNA群体进行了分级分离和比较。因此，检测到一种在rli-感染细胞中不存在，但在未感染细胞中或野生型感染后期存在的tRNA种类。将野生型感染前后分离的该tRNA种类的RNase T1指纹图谱与体外连接的一对CTr5x特异性片段的指纹图谱进行了比较。结果表明，这种tRNA在感染时被切割，随后通过多核苷酸激酶和RNA连接酶反应恢复到其原始或非常相似的形式。有人提出，这种易受影响的宿主tRNA种类的耗尽是pnk-或rli-噬菌体在大肠杆菌CTr5x上受到限制的基础。
