Rosen A, Sarid S, Daniel V
Nucleic Acids Res. 1984 Jun 25;12(12):4893-906. doi: 10.1093/nar/12.12.4893.
A 13.4 kb rat genomic DNA fragment containing two related tRNA gene clusters was isolated from a rat lambda recombinant and analyzed for gene arrangement and nucleotide sequence. One cluster was found to contain a tRNALeuCUG gene while the second contained a tRNALeuCUA pseudogene with multiple base substitutions. The tRNALeu gene was found to possess an intact coding region and a functional transcription termination signal at the 3' end as demonstrated by in vitro transcription and processing of precursors to mature size tRNA. The first tRNA gene cluster was found to contain in addition to tRNALeu, three other transcribable genes coding for tRNAAspGAC(U), tRNAGlyGGA(G) and tRNAGluGAG; the second cluster contained in addition to tRNALeu pseudogene, the tRNAAsp tRNAGly and tRNAGlu genes. Examination of flanking sequences of the corresponding tRNA genes in the two clusters shows no homology at the 5' ends and partial conservation of sequences at the 3'-end region. Genomic rat DNA blot hybridizations show that the tRNALeu gene is distributed together with the tRNAAsp, tRNAGly and tRNAGlu on a 10 fold repeat of 3.2 kb EcoRI fragment.
从大鼠λ重组体中分离出一个13.4 kb的大鼠基因组DNA片段，该片段包含两个相关的tRNA基因簇，并对其基因排列和核苷酸序列进行了分析。发现一个簇含有一个tRNALeuCUG基因，而另一个簇含有一个带有多个碱基取代的tRNALeuCUA假基因。通过对前体进行体外转录和加工至成熟大小的tRNA，发现tRNALeu基因具有完整的编码区和3'端的功能性转录终止信号。发现第一个tRNA基因簇除了tRNALeu外，还包含另外三个可转录基因，分别编码tRNAAspGAC(U)、tRNAGlyGGA(G)和tRNAGluGAG；第二个簇除了tRNALeu假基因外，还包含tRNAAsp、tRNAGly和tRNAGlu基因。对两个簇中相应tRNA基因侧翼序列的检查表明，5'端没有同源性，3'端区域的序列有部分保守性。大鼠基因组DNA印迹杂交表明，tRNALeu基因与tRNAAsp、tRNAGly和tRNAGlu一起分布在一个3.2 kb EcoRI片段的10倍重复序列上。
