Albring M, Griffith J, Attardi G
Proc Natl Acad Sci U S A. 1977 Apr;74(4):1348-52. doi: 10.1073/pnas.74.4.1348.
Almost all (about 95%) of the mitochondrial DNA molecules released by Triton X-100 lysis of HeLa cell mitochondria in the presence of 0.15 M salt are associated with a single protein-containing structure varying in appearance between a 10-20 nm knob and a 100-500 nm membrane-like patch. Analysis by high resolution electron microscopy and by polyacrylamide gel electrophoresis after cleavage of mitochondrial DNA with the endonucleases EcoRI, HindIII, and Hpa II has shown that the protein structure is attached to the DNA in the region of the D-loop, and probably near the origin of mitochondrial DNA replication. The data strongly suggest that HeLa cell mitochondrial DNA is attached in vivo to the inner mitochondrial membrane at or near the origin of replication, and that a membrane fragment of variable size remains associated with the DNA during the isolation. After sodium dodecyl sulfate extraction of mitochondrial DNA, a small 5-10 nm protein is found at the same site on a fraction of the mitochondrial DNA molecules.
在0.15M盐存在的情况下，用Triton X-100裂解HeLa细胞线粒体所释放的几乎所有（约95%）线粒体DNA分子都与一种含蛋白质的结构相关联，该结构外观各异，介于10 - 20纳米的瘤状突起和100 - 500纳米的膜状斑块之间。用核酸内切酶EcoRI、HindIII和Hpa II切割线粒体DNA后，通过高分辨率电子显微镜和聚丙烯酰胺凝胶电泳分析表明，该蛋白质结构附着于D环区域的DNA上，可能靠近线粒体DNA复制起点。数据有力地表明，HeLa细胞线粒体DNA在体内附着于线粒体内膜的复制起点处或其附近，并且在分离过程中，大小可变的膜片段与DNA保持关联。用十二烷基硫酸钠提取线粒体DNA后，在一部分线粒体DNA分子的相同位点发现了一种5 - 10纳米的小蛋白质。
