Fukuhara H, Bolotin-Fukuhara M
Mol Gen Genet. 1976 Apr 23;145(1):7-17. doi: 10.1007/BF00331551.
Mitochondrial transfer RNA genes have been ordered relative to the position of five mitochondrial drug resistance markers, namely, chloramphenicol (C),1 erythromycin (E), oligomycin I and II (OI, OII), and paromomycin (P). Forty-six petite yeast clones that were genetically characterized with respect to these markers were used for a study of these relationships. Different regions of the mitochondrial genome are deleted in these individual mutants, resulting in variable loss of genetic markers. Mitochondrial DNA was isolated from each mutant strain and hybridized with eleven individual mitochondrial transfer RNAs. The following results were obtained: i) Of the seven petite clones that retained C, E, and P resistance markers (but not O1 or O11), four carried all eleven transfer RNA genes examined; the other three clones lost several transfer RNA genes, probably by secondary internal deletion; ii) Prolyl and valyl transfer RNA genes were located close to the P marker, whereas the histidyl transfer RNA gene was close to the C marker; iii) Except for a glutamyl transfer RNA gene that was loosely associated with the O1 region, no other transfer RNA genes were found in petite clones retaining only the O1 and/or the OII markers; and iv) Two distinct mitochondrial genes were found for glutamyl transfer RNA, they were not homologous in DNA sequence and were located at two separate loci. The data indicate that the petite mitochondrial genome is the result of a primary deletion followed by successive additional deletions. Thus an unequivocal gene arrangement cannot be readily established by deletion mapping with petite mutants alone. Nevertheless, we have derived a tentative circular map of the yeast mitochondrial genome from the data; the map indicates that all but one of the transfer RNA genes are found between the C and P markers without forming a tight cluster. The following arrangement is suggested: -P-pro-val-ile-(phe, ala, tyr, asp)-glu2- (lys-leu)-his-C-E-O1-glu1-OII-P-.
线粒体转移RNA基因已根据五个线粒体抗药标记的位置进行了排序，这五个标记分别是氯霉素（C）、红霉素（E）、寡霉素I和II（OI、OII）以及巴龙霉素（P）。对46个在这些标记方面具有遗传特征的小菌落酵母克隆进行了这些关系的研究。在这些单个突变体中，线粒体基因组的不同区域被删除，导致遗传标记的可变丢失。从每个突变菌株中分离出线粒体DNA，并与11种单个线粒体转移RNA进行杂交。得到了以下结果：i）在保留C、E和P抗性标记（但不保留O1或OII）的7个小菌落克隆中，4个携带了所检测的全部11个转移RNA基因；其他3个克隆丢失了几个转移RNA基因，可能是通过二次内部删除；ii）脯氨酰和缬氨酰转移RNA基因位于靠近P标记的位置，而组氨酰转移RNA基因靠近C标记；iii）除了一个与O1区域松散相关的谷氨酰转移RNA基因外，在仅保留O1和/或OII标记的小菌落克隆中未发现其他转移RNA基因；iv）发现了两个不同的线粒体基因用于谷氨酰转移RNA，它们在DNA序列上不同源，且位于两个不同的位点。数据表明，小菌落线粒体基因组是一次主要删除后接着连续进行额外删除的结果。因此，仅通过用小菌落突变体进行删除图谱分析，不能轻易确定明确的基因排列。尽管如此，我们根据这些数据得出了酵母线粒体基因组的一个初步环状图谱；该图谱表明，除了一个转移RNA基因外，所有其他转移RNA基因都位于C和P标记之间，且没有形成紧密的簇。建议的排列如下：-P-脯-缬-异亮-（苯丙、丙、酪、天冬）-谷2-（赖-亮）-组-C-E-O1-谷1-OII-P- 。
