Kapler G M, Zhang K, Beverley S M
Nucleic Acids Res. 1987 Apr 24;15(8):3369-83. doi: 10.1093/nar/15.8.3369.
The 5' structure of mRNA transcribed from the dihydrofolate reductase-thymidylate synthase (DHFR-TS) gene of the protozoan parasite Leishmania major has been characterized. S1 nuclease mapping identifies a heterogenous 5' structure which is not affected by growth phase or developmental stage. The DNA sequence of the 5' region of the DHFR-TS gene does not reveal homology with other trypanosomatid genes, eukaryotic consensus genetic elements, or the mammalian DHFR promoter element. This latter finding is especially significant as we show that the 5' region of the E. coli DHFR gene exhibits homology to the mammalian DHFR promoter element, despite their greater evolutionary distance.
原生动物寄生虫硕大利什曼原虫二氢叶酸还原酶-胸苷酸合成酶（DHFR-TS）基因转录的mRNA的5'结构已得到表征。S1核酸酶图谱分析确定了一种异质的5'结构，该结构不受生长阶段或发育阶段的影响。DHFR-TS基因5'区域的DNA序列与其他锥虫基因、真核共有遗传元件或哺乳动物DHFR启动子元件均无同源性。后一项发现尤为重要，因为我们发现，尽管大肠杆菌DHFR基因与哺乳动物DHFR基因在进化上距离较远，但其5'区域与哺乳动物DHFR启动子元件具有同源性。
