INTRASPECIFIC NUCLEOTIDE-SEQUENCE VARIABILITY SURROUNDING THE ORIGIN OF REPLICATION IN HUMAN MITOCHONDRIAL-DNA
INTRASPECIFIC NUCLEOTIDE-SEQUENCE VARIABILITY SURROUNDING THE ORIGIN OF REPLICATION IN HUMAN MITOCHONDRIAL-DNA
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DOI：
10.1016/0378-1119(83)90145-2
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发表时间：
1983-01-01
期刊：
影响因子：
3.5
通讯作者：
SUGINO, A
中科院分区：
文献类型：
--
作者：
GREENBERG, BD;NEWBOLD, JE;SUGINO, A
从11个人类胎盘中克隆了人类线粒体[大鼠]DNA的主要非编码区。对其中5个克隆的部分核苷酸序列进行了测定，它们在h链复制起点附近最多共享900 bp[碱基对]。这些序列与先前确定的其他序列的比对揭示了核苷酸替换和插入/删除事件的惊人模式。分化序列的水平显著超过编码区分化的报道估计。还定义了两个特别高变的区域。96%以上的碱基变化是过渡，长度变化仅发生在连续重复延伸的单核苷酸或二核苷酸片段的添加或删除。线粒体基因组的这个区域包含了复制和转录的起始位点，在物种中就序列和长度而言是最不保守的。尽管总体上缺乏一级序列保守性，但在该区域内可用的哺乳动物mtDNA序列中出现了一些一致性。在物种之间，一个保守的线性阵列的特征延伸存在，但不同的主要序列。在人类中，一些保守的类核蛋白片段出现在从其他物种的mtDNA中删除的区域内。这些观察结果与核苷酸序列的物种特异性和物种之间必要的遗传功能的保存一致。这为哺乳动物线粒体中蛋白质-核酸相互作用的进化提供了一个模型。
The major noncoding region of human mitochondrial [rat] DNA was cloned from 11 human placentas. Partial nucleotide sequences of 5 of these clones were determined and they share a maximum of 900 bp [base pair] around the origin of H-strand replication. Alignment of these sequences with others previously determined has revealed a striking pattern of nucleotide substitutions and insertion/deletion events. The level of sequence of divergence significantly exceeds the reported estimates of divergence in coding regions. Two particularly hypervariable regions were also defined. More than 96% of the base changes are transitions, and length alterations occurred exclusively by addition or deletion or mono- or dinucleotide segments within serially repeating stretches. This region of the mitochondrial genome, which contains the initiation sites for replication and transcription, is the least conserved among species with respect to both sequence and length. Despite this overall lack of primary sequence conservation, several consistencies appear among the available mammalian mtDNA sequences within this region. Between species, a conserved linear array of characteristic stretches exists which nonetheless differ in primary sequence. Among humans, several conserved blocks of nucletoides appear within domains deleted from the mtDNA of other species. These observations are consistent with both a species-specificity of nucleotide sequence, and a preservation of the necessary genetic functions among species. This provides a model for the evolution of protein-nucleic acid interactions in mammalian mitochondria.