Clarkson S G, Kurer V, Smith H O
Cell. 1978 Jul;14(3):713-24. doi: 10.1016/0092-8674(78)90253-2.
3.18 kb fragments of X. laevis DNA coding for tRNA 1 met have been inserted into a lambda vector via Hind III termini and cloned in E. coli. The organization of one cloned fragment has been analyzed by restriction endonuclease digestion and RNA-DNA hybridization. From the distribution of sites for three enzymes, this fragment appears to be typical of the majority of X. laevis tandem tDNA 1 met repeat units. Evidence is presented to suggest that it contains two genes coding for tRNA 1 met and at least one gene coding for a second as yet unidentified 4S RNA species. The two tRNA 1 met genes are located on the same DNA strand 0.96 and 1.38 kb from one end of the repeat unit. A detailed restriction map for 19 enzymes reveals that the spacers between these genes are not identical, and it provides no indication of short repetitive sequence elements within the spacers.
编码tRNA1met的非洲爪蟾DNA的3.18 kb片段已通过Hind III末端插入λ载体，并在大肠杆菌中克隆。通过限制性内切酶消化和RNA-DNA杂交分析了一个克隆片段的结构。从三种酶的位点分布来看，该片段似乎是大多数非洲爪蟾串联tDNA1met重复单元的典型代表。有证据表明它包含两个编码tRNA1met的基因和至少一个编码另一种尚未鉴定的4S RNA物种的基因。两个tRNA1met基因位于重复单元一端0.96和1.38 kb处的同一条DNA链上。19种酶的详细限制性图谱显示，这些基因之间的间隔区并不相同，并且没有显示出间隔区内存在短重复序列元件。
