Akins R A, Kelley R L, Lambowitz A M
Cell. 1986 Nov 21;47(4):505-16. doi: 10.1016/0092-8674(86)90615-x.
The Mauriceville (3.6 kb) and Varkud (3.8 kb) mitochondrial plasmids of Neurospora are closely related, closed circular DNAs whose nucleotide sequences and genetic organization suggest relationships to mitochondrial introns and retrotransposons. Here we isolated mutants whose growth is impaired as a result of malevolent behavior of these plasmids. All 12 mutants contain variant plasmids that are suppressive relative to mtDNA, and ten also contain defective mtDNAs. All the suppressive plasmids contain small insertions, generally including a mitochondrial tRNA sequence, at or near the major 5' RNA start site. The structure of the suppressive plasmids suggests that they were generated via an RNA intermediate and a reverse transcription step. At least three of the mutants contain defective mtDNAs into which mitochondrial plasmid sequences have integrated. Sequences at the plasmid-mtDNA junctions are also consistent with integration via an RNA intermediate.
粗糙脉孢菌的莫里斯维尔（3.6 kb）和瓦尔库德（3.8 kb）线粒体质粒密切相关，是闭环DNA，其核苷酸序列和基因组织表明与线粒体内含子和逆转录转座子有关。在这里，我们分离出了一些突变体，由于这些质粒的有害行为，它们的生长受到了损害。所有12个突变体都含有相对于线粒体DNA具有抑制性的变异质粒，其中10个还含有缺陷型线粒体DNA。所有抑制性质粒在主要5'RNA起始位点或其附近都有小的插入片段，通常包括一个线粒体tRNA序列。抑制性质粒的结构表明它们是通过RNA中间体和逆转录步骤产生的。至少有三个突变体含有缺陷型线粒体DNA，线粒体质粒序列已整合到其中。质粒-线粒体DNA连接处的序列也与通过RNA中间体进行的整合一致。
