Kikuchi Y, Hirai K, Gunge N, Hishinuma F
EMBO J. 1985 Jul;4(7):1881-6. doi: 10.1002/j.1460-2075.1985.tb03864.x.
The terminal structures of deletion derivatives of linear DNA killer plasmid from yeast were analyzed. The yeast Kluyveromyces lactis harbors two unique double-stranded linear DNA killer plasmids, pGKL1 of 8.9 kb and pGKL2 of 13.4 kb. The killer toxin and the resistance to the killer are coded by pGKL1, while pGKL2 is required for the maintenance of pGKL1 in the cell. When the pGKL plasmids from K. lactis were transferred into Saccharomyces cerevisiae by transformation, non-killer transformants harboring pGKL2 and new plasmids, F1 of 7.8 kb and F2 of 3.9 kb, were obtained. F2 was shown to be a linear DNA arising from a 5-kb deletion of the right part of pGKL1. F1 was an inverted dimer of F2. Here we show that F2 has two different terminal structures: one end has a protein attached at the 5' terminus whereas the two strands of duplex are linked together at the other end, thus forming a hairpin structure. This is a novel type of autonomously replicating DNA molecule.
对来自酵母的线性DNA杀伤质粒缺失衍生物的末端结构进行了分析。乳酸克鲁维酵母含有两种独特的双链线性DNA杀伤质粒，8.9 kb的pGKL1和13.4 kb的pGKL2。杀伤毒素和对杀伤的抗性由pGKL1编码，而pGKL2是pGKL1在细胞中维持所必需的。当通过转化将来自乳酸克鲁维酵母的pGKL质粒转移到酿酒酵母中时，获得了携带pGKL2和新质粒（7.8 kb的F1和3.9 kb的F2）的非杀伤转化体。F2被证明是由pGKL1右部5 kb缺失产生的线性DNA。F1是F2的反向二聚体。在此我们表明F2有两种不同的末端结构：一端在5'末端附着有蛋白质，而双链的两条链在另一端连接在一起，从而形成发夹结构。这是一种新型的自主复制DNA分子。
