LEFT-HANDED DNA INVIVO
LEFT-HANDED DNA INVIVO
复制标题
DOI：
10.1126/science.3313728
复制
发表时间：
1987-11-06
期刊：
影响因子：
56.9
通讯作者：
WELLS, RD
中科院分区：
文献类型：
--
作者：
JAWORSKI, A;HSIEH, WT;WELLS, RD
左手DNA在大肠杆菌中存在并引起生物反应。将编码温度敏感性EcoRI甲基化酶（MEco RI）基因的质粒与含有插入物的不同质粒共转化，所述插入物具有不同的形成左手螺旋或十字形的能力，其中靶EcoRI位点在插入物的中心或末端。抑制甲基化在体内被发现的最长的左手（大概是Z）螺旋的稳定插入。用纯化的MEco RI进行的体外甲基化与体内结果一致。超螺旋在体外诱导的初级螺旋结构的变化提供了确认，左手螺旋负责这种行为。在某些情况下，体内左手插入片段的存在会导致特异性缺失和质粒不相容性。
Left-handed DNA is shown to exist and elicit a biological repsonse in Escherichia coli. A plasmid encoding the gene for a temperature-sensitive Eco RI methylase (MEco RI) was cotransformed with different plasmids containing inserts that had varying capacities to form left-handed helices or cruciforms with a target Eco RI site in the center or at the ends of the inserts. Inhibition of methylation in vivo was found for the stable inserts with the longest left-handed (presumably Z) helices. In vitro methylation with the purified MEco RI agreed with the results in vivo. Supercoil-induced changes in the structure of the primary helix in vitro provided confirmation that left-handed helices were responsible for this behavior. The presence in vivo of left-handed inserts elicits specific deletions and plasmid incompatibilities in certain instances.