Snyder M, Buchman A R, Davis R W
Nature. 1986;324(6092):87-9. doi: 10.1038/324087a0.
DNA fragments that show retarded electrophoretic mobility through polyacrylamide gels have been found in both prokaryotes and eukaryotes. In the case of kinetoplast DNA, evidence has been presented that the DNA is curved or 'bent'. Bent DNA has previously been found at the lambda and simian virus 40 (SV40) DNA replication origins. Here we show the existence of bent DNA at a yeast autonomously replicating sequence (ARS1), a putative replication origin. The bent DNA has been localized to a 40-55 base pair (bp) segment and contains six (A)3-5 stretches (that is, six poly(A) stretches, three to five nucleotides in length) phased approximately every 10.5 bp. This region contains a DNA binding site for a yeast protein factor. This site lies at the 3' end of the TRP1 gene, in a region devoid of nucleosomes, and is positioned 80 bp away from the ARS consensus sequence; removal of this region impairs ARS function in vivo. The bent DNA may be involved in transcription termination or the prevention of nucleosome assembly in this region.
在原核生物和真核生物中均发现了在聚丙烯酰胺凝胶中电泳迁移率减慢的DNA片段。就动质体DNA而言，已有证据表明该DNA是弯曲的。此前在λ噬菌体和猴病毒40（SV40）的DNA复制起点处发现过弯曲的DNA。在此我们展示了在酵母自主复制序列（ARS1，一个假定的复制起点）处存在弯曲的DNA。弯曲的DNA已定位到一个40 - 55个碱基对（bp）的片段，其中包含六个（A）3 - 5序列（即六个聚腺苷酸序列，长度为三到五个核苷酸），大约每隔10.5 bp出现一个。该区域包含一个酵母蛋白质因子的DNA结合位点。这个位点位于TRP1基因的3'端，处于一个没有核小体的区域，并且距离ARS共有序列80 bp；去除该区域会损害ARS在体内的功能。弯曲的DNA可能参与了该区域的转录终止或核小体组装的阻止。
