Lagosky P A, Taylor G R, Haynes R H
Department of Biology, York University, Toronto, Ontario, Canada.
Nucleic Acids Res. 1987 Dec 23;15(24):10355-71. doi: 10.1093/nar/15.24.10355.
The complete nucleotide sequence of a 1957 bp DNA fragment containing the dihydrofolate reductase gene (DFR1) of the yeast Saccharomyces cerevisiae is presented. Within this region a single open reading frame of 633 base pairs was found which is capable of encoding a 211 amino acid residue protein with a calculated Mr of 24,233. The amino acid sequence derived from the yeast DFR1 gene shows limited homology with sequences from both eukaryotic and non-eukaryotic DHFR enzymes. Northern blot hybridization reveals that the mRNA from this gene is a 900 base polyadenylated transcript. Yeast strains containing the cloned DFR1 gene on multicopy number shuttle vector plasmids show dramatically enhanced methotrexate resistance. Consensus DNA sequences responsible for RNA polymerase II interaction and general amino acid control in S. cerevisiae are located within the 5'-noncoding region with respect to the open reading frame. The DNA fragment containing these sequences has been shown to be necessary for DFR1 gene expression in both S. cerevisiae and E. coli.
本文给出了包含酿酒酵母二氢叶酸还原酶基因（DFR1）的1957bp DNA片段的完整核苷酸序列。在该区域内发现了一个633个碱基对的单一开放阅读框，它能够编码一个含有211个氨基酸残基的蛋白质，计算所得的分子量为24233。来自酵母DFR1基因的氨基酸序列与真核和非真核二氢叶酸还原酶（DHFR）的序列显示出有限的同源性。Northern印迹杂交表明，该基因的mRNA是一个900个碱基的多聚腺苷酸化转录本。在多拷贝穿梭载体质粒上含有克隆的DFR1基因的酵母菌株对甲氨蝶呤的抗性显著增强。负责RNA聚合酶II相互作用和酿酒酵母一般氨基酸调控的共有DNA序列位于相对于开放阅读框的5'-非编码区内。含有这些序列的DNA片段已被证明对于DFR1基因在酿酒酵母和大肠杆菌中的表达都是必需的。
