Vnencak-Jones C L, Wahab S Z, Zehner Z E, Holmes W M
Department of Human Genetics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298.
Mol Cell Biol. 1987 Nov;7(11):4134-8. doi: 10.1128/mcb.7.11.4134-4138.1987.
A third nonallelic locus of the human methionyl-tRNA multigene family (tRNA(iMet-3) was isolated. This gene, unlike two other tRNA(iMet) loci, lacks a remarkable run of T and C residues which functions as a termination of transcription signal. Instead, three tandem termination signals, each containing no more than four thymidylate residues, function as relatively inefficient termination signals. As a result, polymerase readthrough generates at least three transcripts in vitro. The efficiency of apparent termination varies significantly at these sites. All resulting transcripts appear to be processed in vitro.
分离出了人类甲硫氨酰 - tRNA多基因家族的第三个非等位基因座(tRNA(iMet-3))。与其他两个tRNA(iMet)基因座不同,该基因缺乏一串显著的T和C残基,而这串残基作为转录终止信号发挥作用。取而代之的是三个串联的终止信号,每个信号包含不超过四个胸苷酸残基,作为相对低效的终止信号。因此,聚合酶通读在体外产生至少三种转录本。在这些位点,明显的终止效率差异很大。所有产生的转录本在体外似乎都经过了加工。