Is there left-handed DNA at the ends of yeast chromosomes?
Is there left-handed DNA at the ends of yeast chromosomes?
复制标题
酵母染色体末端是否有左手DNA？
作者：
Walmsley,RM;Szostak,JW;Petes,TD
交替共聚物聚（dGdT · dCdA）的踪迹已在各种真核生物中观察到1。这些片段特别令人感兴趣，因为该序列的均聚物可以在体外左旋Z形成DNA 2。我们已经发现，酵母Saccharomyces gallae在分散的基因组位置上含有至少30个聚（GT）片段。我们在这里显示，这些大片的一个子集位于酵母染色体的末端（端粒）。此外，我们表明，聚（dGdT·dCdA）tracts添加到染色体外核糖体DNA分子的四膜虫在酵母中克隆时的末端。这些数据代表了第一次报道的关联之间的同源序列和染色体结构。
Tracts of the alternating copolymer poly(dGdT · dCdA) have been observed in a variety of eukaryotes1. Such tracts are of particular interest since homopolymers of this sequence can existin vitroas left-handed Z form DNA2. We have found that the yeastSaccharomyces cerevisiaecontains at least 30 poly(GT) tracts at dispersed genomic locations. We show here that one subset of these tracts is located at the ends (telomeres) of the yeast chromosome. In addition, we show that poly(dGdT·dCdA) tracts are added to the ends of the extra-chromosomal ribosomal DNA molecules ofTetrahymenawhen cloned in yeast. These data represent the first reported association between a homopolymeric sequence and a chromosome structure.