PRIMING OF HUMAN MITOCHONDRIAL-DNA REPLICATION OCCURS AT THE LIGHT-STRAND PROMOTER
PRIMING OF HUMAN MITOCHONDRIAL-DNA REPLICATION OCCURS AT THE LIGHT-STRAND PROMOTER
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DOI：
10.1073/pnas.82.2.351
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发表时间：
1985-01-01
影响因子：
11.1
通讯作者：
CLAYTON, DA
中科院分区：
文献类型：
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作者：
CHANG, DD;CLAYTON, DA
人类[线粒体] mtDNA每条链的转录启动子位于置换环区重链DNA复制起点附近。重链合成的起始是mtDNA复制的第一步。对来自培养的人类细胞的线粒体的置换环核酸的5“和3”图谱位置的分析揭示了RNA的3“末端（其5”末端在独特位点处图谱）与DNA链的5“末端之间的密切对应。RNA种类的5“末端全部定位在基因组序列中的核苷酸位置407处，其精确地对应于先前在体外确定的主要5”转录起始位点，其包含在轻链启动子序列内。置换环重链DNA映射紧邻这些RNA的3“末端，并且RNA和DNA之间的这些过渡点位于模板序列中的短保守序列块内。复制在主要转录启动子处起始，随后精确切割初级转录物以提供适当的引物种类。
Individual promoters for transcription of each strand of human [mitochondrial] mtDNA are located near the origin of heavy-strand DNA replication in the displacement-loop region. Initiation of heavy-strand synthesis represents the first event in mtDNA replication. Analyses of the 5'' and 3'' map positions of displacement-loop nucleic acids from mitochondria of cultured human cells reveal a close correspondence between the 3'' ends of RNA, whose 5'' ends map at a unique site, and the 5'' ends of DNA strands. The 5'' ends of the RNA species all map at nucleotide position 407 in the genomic sequence, which corresponds exactly to the major 5'' transcriptional start site, determined previously in vitro, that is contained within the light-strand promoter sequence. Displacement-loop heavy-stand DNAs map immediately adjacent to the 3'' termini of these RNA, and these transition points between RNA and DNA lie within short conserved sequence blocks in the template sequence. Replication is initiated at the major transcriptional promoter with subsequent precise cleavage of primary transcripts to provide the appropriate primer species.