LINEAR MITOCHONDRIAL DNAS OF YEASTS - CLOSED-LOOP STRUCTURE OF THE TERMINI AND POSSIBLE LINEAR-CIRCULAR CONVERSION MECHANISMS
LINEAR MITOCHONDRIAL DNAS OF YEASTS - CLOSED-LOOP STRUCTURE OF THE TERMINI AND POSSIBLE LINEAR-CIRCULAR CONVERSION MECHANISMS
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DOI：
10.1128/mcb.13.4.2315
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发表时间：
1993-04-01
影响因子：
5.3
通讯作者：
FUKUHARA, H
中科院分区：
文献类型：
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作者：
DINOUEL, N;DRISSI, R;FUKUHARA, H
对三种酵母的线形线粒体DNA(MtDNA)末端结构进行了研究。通过酶切、碱变性和克隆末端测序，结果表明，在Pijperi和P.jadinii中，线形mtDNA的两端都是由单链环共价连接而成的，与痘苗病毒DNA的情况一样。左右两个环路序列处于两个方向中的任何一个，表明存在触发器反转机制。与末端环相邻的是反向末端重复序列。柳杉的线粒体DNA似乎具有类似的结构，尽管末端环不能被直接证明。电子显微镜显示，在线性分子中，存在少量的环形DNA，主要是单体长度的DNA。考虑了复制的线性和圆形模型，并讨论了线性和圆形之间可能的转换机制。环状中间体内的反向重复序列之间的触发器倒置机制可能涉及线形mtDNA的产生。
The terminal structure of the linear mitochondrial DNA (mtDNA) from three yeast species has been examined. By enzymatic digestion, alkali denaturation, and sequencing of cloned termini, it was shown that in Pichia pijperi and P. jadinii, both termini of the linear mtDNA were made of a single-stranded loop covalently joining the two strands, as in the case of vaccinia virus DNA. The left and right loop sequences were in either of two orientations, suggesting the existence of a flip-flop inversion mechanism. Contiguous to the terminal loops, inverted terminal repeats were present. The mtDNA from Williopsis mrakii seems to have an analogous structure, although terminal loops could not be directly demonstrated. Electron microscopy revealed the presence, among linear molecules, of a small number of circular DNAs, mostly of monomer length. Linear and circular models of replication are considered, and possible conversion mechanisms between linear and circular forms are discussed. A flip-flop inversion mechanism between the inverted repeat sequences within a circular intermediate may be involved in the generation of the linear form of mtDNA.