Lisowsky T, Michaelis G
Botanisches Institut, Universität Düsseldorf, Federal Republic of Germany.
Mol Gen Genet. 1988 Oct;214(2):218-23. doi: 10.1007/BF00337714.
A genomic DNA fragment from yeast was isolated by transforming a temperature sensitive pet mutant. This mutant, pet-ts 798, has previously been characterized by its altered mitochondrial transcription apparatus. Subcloning and DNA sequencing of the genomic DNA fragment identified a reading frame responsible for the restoration of the pet-ts phenotype. The reading frame of 1023 bp is transcribed as an RNA of about 1100 nucleotides. The putative protein of 40 kDa possesses a hydrophobic amino-terminus and acidic and basic domains characteristic of recently described transcriptional activators. The inactivation of the functional gene by the introduction of an insertion fragment into the reading frame, leads to a stable pet phenotype. Further analysis of this mutant created by gene disruption makes clear that the respiratory defect is caused by the complete loss of mitochondrial DNA. Experimental evidence is given that the cloned gene acts as an intergenic suppressor of the mutant pet-ts 798. Therefore, the isolated gene represents a new factor involved in the regulation of mitochondrial replication and transcription.
通过转化温度敏感型pet突变体，从酵母中分离出一个基因组DNA片段。这个突变体pet-ts 798，先前已通过其改变的线粒体转录装置进行了表征。对基因组DNA片段进行亚克隆和DNA测序，确定了一个负责恢复pet-ts表型的阅读框。1023 bp的阅读框转录为约1100个核苷酸的RNA。推测的40 kDa蛋白质具有疏水性氨基末端以及最近描述的转录激活因子特有的酸性和碱性结构域。通过将插入片段引入阅读框使功能基因失活，导致稳定的pet表型。对通过基因破坏产生的该突变体的进一步分析表明，呼吸缺陷是由线粒体DNA的完全丧失引起的。实验证据表明，克隆的基因作为突变体pet-ts 798的基因间抑制子起作用。因此，分离出的基因代表了一个参与线粒体复制和转录调控的新因子。
