来自高等植物藜（Chenopodium album (L.)）的线粒体滚环质粒mp1的独特特征。
Unique features of the mitochondrial rolling circle-plasmid mp1 from the higher plant Chenopodium album (L.).
作者信息
Backert S, Meissner K, Börner T
机构信息
Institut für Biologie, Humboldt-Universität zu Berlin, Chausseestrasse 117, D-10115 Berlin, Germany.
出版信息
Nucleic Acids Res. 1997 Feb 1;25(3):582-89. doi: 10.1093/nar/25.3.582.
We analyzed the structure and replication of the mitochondrial (mt) circular DNA plasmid mp1 (1309 bp) from the higher plant Chenopodium album(L.). Two dimensional gel electrophoresis (2DE) revealed the existence of oligomers of up to a decamer in addition to the prevailing monomeric form. The migration behavior of cut replication intermediates during 2DE was consistent with a rolling circle (RC) type of replication. We detected entirely single-stranded (ss) plasmid copies hybridizing only with one of the two DNA strands. This result indicates the occurence of an asymmetric RC replication mechanism. mp1 has, with respect to its replication, some unique features compared with bacterial RC plasmids. We identified and localized a strand-specific nicking site (origin of RC replication) on the plasmid by primer extension studies. Nicks in the plasmid were found to occur at any one of six nucleotides (TAAG/GG) around position 735 of the leading strand. This sequence shows no homology to origin motifs from known bacterial RC replicons. mp1 is the first described RC plasmid in a higher plant.
我们分析了高等植物藜（Chenopodium album (L.)）中线粒体（mt）环状DNA质粒mp1（1309 bp）的结构和复制情况。二维凝胶电泳（2DE）显示，除了占主导地位的单体形式外，还存在多达十聚体的寡聚体。在2DE过程中，切割后的复制中间体的迁移行为与滚环（RC）复制类型一致。我们检测到完全单链（ss）的质粒拷贝，它们仅与两条DNA链中的一条杂交。这一结果表明存在不对称RC复制机制。与细菌RC质粒相比，mp1在复制方面具有一些独特的特征。通过引物延伸研究，我们在质粒上鉴定并定位了一个链特异性切口位点（RC复制起点）。发现质粒中的切口出现在前导链735位左右的六个核苷酸（TAAG/GG）中的任何一个处。该序列与已知细菌RC复制子的起点基序没有同源性。mp1是高等植物中首次描述的RC质粒。
Zotero 插件