Fonzi W A, Sypherd P S
J Biol Chem. 1987 Jul 25;262(21):10127-33.
The nucleotide sequence was determined for a 3-kilobase genomic fragment containing the ornithine decarboxylase gene of Saccharomyces cerevisiae. The fragment contained two open reading frames. Gene disruption localized the ornithine decarboxylase gene to a 1398-nucleotide open reading frame. Transcription of the yeast gene initiated at several sites 171 to 211 nucleotides 5' of the translational start site. The 3' end of the transcript extended approximately 300 nucleotides beyond the end of the ornithine decarboxylase coding region and contained two copies of the yeast ARS core sequence. Translation of the ornithine decarboxylase gene appeared to initiate at the first AUG condon of the open reading frame based upon translational fusions with the Escherichia coli beta-galactosidase gene. Since no introns were apparent, the 1398-nucleotide open reading frame was predicted to encode a 466-amino acid protein with a calculated Mr = 52,369. The deduced protein differed significantly in size from previous reports on yeast ornithine decarboxylase, but was very similar in size to mammalian ornithine decarboxylase. When the predicted amino acid sequence of yeast ornithine decarboxylase was compared with that of the mouse enzyme, alignment of the sequences revealed that 40% of the amino acid residues were identical. Chou-Fasman predictions of the secondary structure of the two enzymes indicated that secondary structure was also highly conserved.
测定了酿酒酵母鸟氨酸脱羧酶基因所在的一个3千碱基基因组片段的核苷酸序列。该片段包含两个开放阅读框。基因破坏将鸟氨酸脱羧酶基因定位到一个1398核苷酸的开放阅读框。酵母基因的转录起始于翻译起始位点5'端171至211个核苷酸处的几个位点。转录本的3'端在鸟氨酸脱羧酶编码区末端之外延伸约300个核苷酸，并包含酵母ARS核心序列的两个拷贝。基于与大肠杆菌β-半乳糖苷酶基因的翻译融合，鸟氨酸脱羧酶基因的翻译似乎起始于开放阅读框的第一个AUG密码子。由于未发现内含子，预计1398核苷酸的开放阅读框编码一个466个氨基酸的蛋白质，计算的Mr = 52369。推导的蛋白质大小与先前关于酵母鸟氨酸脱羧酶的报道有显著差异，但与哺乳动物鸟氨酸脱羧酶的大小非常相似。当将酵母鸟氨酸脱羧酶的预测氨基酸序列与小鼠酶的序列进行比较时，序列比对显示40%的氨基酸残基是相同的。两种酶二级结构的Chou-Fasman预测表明二级结构也高度保守。
