Miyajima A, Shibuya M, Kuchino Y, Kaziro Y
Mol Gen Genet. 1981;183(1):13-9. doi: 10.1007/BF00270131.
The transcription of the tufB gene by purified RNA polymerase holoenzyme was studied using the transducing phage lambda rifd 18 DNA and the hybrid plasmid pTUB1 DNA (Miyajima et al. 1979) as templates. The size of tufB mRNA synthesized in this system was about 1,700 nucleotides, and the same strand as for rrnB was transcribed. By electron microscopic examination of the R-loop formed between lambda fus3 DNA and tufB mRNA synthesized under the direction of pTUB1 DNA, it was found that the untranslated sequence of about 500 nucleotides is at the 5' end of tufB mRNA. The sequencing of the 5' region of tufB mRNA synthesized on the truncated template has revealed that the tufB gene is cotranscribed with its upstream genes for four tRNAs (thrU, tyrU, glyT, and thrT). The synthesis of this mRNA molecule is completely abolished by low concentrations of ppGpp. Neither pppGpp, ppGp, nor pGpp was effective as inhibitor in this cell-free system.
利用转导噬菌体λrifd 18 DNA和杂交质粒pTUB1 DNA（宫岛等人，1979年）作为模板，研究了纯化的RNA聚合酶全酶对tufB基因的转录。在该系统中合成的tufB mRNA大小约为1700个核苷酸，并且转录的是与rrnB相同的链。通过电子显微镜检查在λfus3 DNA与在pTUB1 DNA指导下合成的tufB mRNA之间形成的R环，发现约500个核苷酸的非翻译序列位于tufB mRNA的5'端。对在截短模板上合成的tufB mRNA的5'区域进行测序表明，tufB基因与其上游的四个tRNA（thrU、tyrU、glyT和thrT）基因共转录。低浓度的ppGpp可完全抑制这种mRNA分子的合成。在这个无细胞系统中，pppGpp、ppGp和pGpp均无抑制作用。
