Pardue M L, Fostel J M, Cech T R
Nucleic Acids Res. 1984 Feb 24;12(4):1991-9. doi: 10.1093/nar/12.4.1991.
The location of proteins on the mitochondrial DNA (mtDNA) of Drosophila virilis was investigated by Me3 psoralen photoreaction of mitochondria isolated from embryos. After photoreaction the mtDNA was purified and the pattern of DNA cross-linking was determined by electron microscopy of the DNA under totally denaturing conditions. The transcribed regions of the mtDNA molecule contained some uncross-linked regions, but such regions were infrequent and randomly distributed. In contrast, the A + T-rich region around the origin of replication of the mtDNA was usually protected from psoralen cross-linking. The data were best fit by two protected sites, each approximately 400 base pairs, compared to the four 400 base pair sites observed in the equivalent region of D. melanogaster mtDNA [Potter et al. (1980) Proc. Nat. Acad. Sci. USA 77, 4118-4122]. Thus this region of the mtDNA appears to be involved in a DNA-protein structure that is highly conserved even though the DNA sequence has diverged rapidly relative to protein-coding sequences.
通过对从胚胎中分离出的线粒体进行甲基补骨脂素光反应，研究了果蝇线粒体DNA（mtDNA）上蛋白质的定位。光反应后，纯化mtDNA，并在完全变性条件下通过DNA的电子显微镜观察确定DNA交联模式。mtDNA分子的转录区域包含一些未交联区域，但这些区域很少且随机分布。相比之下，mtDNA复制起点周围的富含A + T的区域通常可免受补骨脂素交联的影响。与在黑腹果蝇mtDNA等效区域中观察到的四个400碱基对位点相比，数据最符合两个受保护位点，每个位点约400碱基对[波特等人（1980年）美国国家科学院院刊77，4118 - 4122]。因此，mtDNA的该区域似乎参与了一种DNA - 蛋白质结构，尽管相对于蛋白质编码序列而言DNA序列已经快速分化，但这种结构却高度保守。
