Sequences of six genes and several open reading frames in the kinetoplast maxicircle DNA of Leishmania tarentolae.
Sequences of six genes and several open reading frames in the kinetoplast maxicircle DNA of Leishmania tarentolae.
复制标题
DOI：
10.1016/s0021-9258(17)42525-7
复制
发表时间：
1984-12
期刊：
影响因子：
--
通讯作者：
Vidal F. de la Cruzl;N. Neckelmann;Larry Simpsonll
中科院分区：
文献类型：
--
作者：
Vidal F. de la Cruzl;N. Neckelmann;Larry Simpsonll
获得了利什曼原虫动基体大环DNA转录区约80%的DNA序列，并通过与其他生物体已知线粒体基因的氨基酸序列比较，定位了结构基因。通过该方法，鉴定了细胞色素氧化酶亚基I、II和III、细胞色素B和人线粒体未鉴定阅读框4和5的基因。通过比较L. tarentolae基因与那些已知的基因，我们得出结论，TGA编码色氨酸，在大多数其他线粒体系统。这是宇宙遗传密码唯一明显的变化。这6个结构基因与其他物种的同源基因存在不同程度的差异，其中细胞色素氧化酶亚基I最保守，细胞色素氧化酶亚基III最不保守。对L. tarentolae和Trypanosoma brucei发现颠换与转换的比例为1：1，表明这些物种在80 × 10（6）年前彼此分化。在maxicircle序列中还存在几个尚未识别的开放阅读框。这些数据证实了大环DNA具有编码潜力，这代表了其他线粒体系统。
The DNA sequence of approximately 80% of the transcribed region of the kinetoplast maxicircle DNA of Leishmania tarentolae was obtained, and structural genes were localized by comparison of the translated amino acid sequences with those of known mitochondrial genes from other organisms. By this method, the genes for cytochrome oxidase subunits I, II, and III, cytochrome b, and human mitochondrial unidentified reading frames 4 and 5 were identified. By comparing the amino acid sequences of the putative L. tarentolae genes with those of known genes, we conclude that TGA codes for tryptophan, as in most other mitochondrial systems. This is the only apparent change from the universal genetic code. The six identified structural genes show various degrees of divergence from the homologous genes in other species, with cytochrome oxidase subunit I being the most conserved and cytochrome oxidase subunit III being the least conserved. A comparison of the cytochrome b genes from L. tarentolae and Trypanosoma brucei showed that the ratio of transversions to transitions is 1:1, suggesting that these species diverged from each other more than 80 X 10(6) years ago. Several as yet unidentified open reading frames were also present in the maxicircle sequence. These data confirm that maxicircle DNA has a coding potential which typifies other mitochondrial systems.