STRAND-SPECIFIC NUCLEOTIDE COMPOSITION BIAS IN ECHINODERM AND VERTEBRATE MITOCHONDRIAL GENOMES
STRAND-SPECIFIC NUCLEOTIDE COMPOSITION BIAS IN ECHINODERM AND VERTEBRATE MITOCHONDRIAL GENOMES
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DOI：
10.1007/bf02102653
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发表时间：
1991-06-01
影响因子：
3.9
通讯作者：
WATANABE, K
中科院分区：
文献类型：
--
作者：
ASAKAWA, S;KUMAZAWA, Y;WATANABE, K
海星线粒体DNA的基因组织与海胆对应物的基因组织相同，除了报道的包含两个NADH脱氢酶亚基1和2（ND 1和ND 2）的结构基因的约4.6kb片段的倒位。当检查海星、海胆和脊椎动物线粒体DNA中每个结构基因的密码子使用时，令人惊讶的是，以T和G结尾的密码子优先用于重链编码的基因，包括海星ND 1和ND 2，而不是轻链编码的基因，包括海胆ND 1和ND 2。相反，以A和C结尾的密码子优先用于轻链编码的基因，而不是用于重链编码的基因。此外，G-U碱基对在重链编码的tRNA的可能二级结构中比在轻链编码的tRNA中更频繁地发现。这些观察结果表明，存在某种限制作用于各种动物门的线粒体基因组，这导致G和T在一条链上积累，A和C在另一条链上积累。
The gene organization of starfish mitochondrial DNA is identical with that of the sea urchin counterpart except for a reported inversion of an approximately 4.6-kb segment containing two structural genes for NADH dehydrogenase subunits 1 and 2 (ND 1 and ND 2). When the codon usage of each structural gene in starfish, sea urchin, and vertebrate mitochondrial DNAs is examined, it is striking that codons ending in T and G are preferentially used more for heavy strand-encoded genes, including starfish ND 1 and ND 2, than for light strand-encoded genes, including sea urchin ND 1 and ND 2. On the contrary, codons ending in A and C are preferentially used for the light strand-encoded genes rather than for the heavy strand-encoded ones. Moreover, G-U base pairs are more frequently found in the possible secondary structures of heavy strand-encoded tRNAs than in those of light strand-encoded tRNAs. These observations suggest the existence of a certain constraint operating on mitochondrial genomes from various animal phyla, which results in the accumulation of G and T on one strand, and A and C on the other.