ENHANCER ORIGIN INTERACTION IN PLASMID-R6K INVOLVES A DNA LOOP MEDIATED BY INITIATOR PROTEIN
ENHANCER ORIGIN INTERACTION IN PLASMID-R6K INVOLVES A DNA LOOP MEDIATED BY INITIATOR PROTEIN
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DOI：
10.1016/s0092-8674(88)80030-8
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发表时间：
1988-02-12
期刊：
影响因子：
64.5
通讯作者：
BASTIA, D
中科院分区：
文献类型：
--
作者：
MUKHERJEE, S;ERICKSON, H;BASTIA, D
从ori β起始DNA复制质粒R6 K的表达需要ori γ的存在。顺式序列。我们证明了起始蛋白与γ中七个强的串联结合位点的结合。增加蛋白质在存在于ori β中的非常弱的结合位点处的结合。通过远距离的合作性。γβ的通过引发剂的相互作用导致DNA环，如环化增强的新技术所揭示的，并如核酸外切酶III保护、电子显微镜和化学足迹所证实的。蛋白质介导的γ-β的体外相互作用表明γ-与β结合的蛋白质通过DNA成环的DNA序列的复制是在β链起始DNA复制的早期步骤。R6 K的起源
Initiation of DNA replication from ori .beta. of plasmid R6K requires the presence of the ori .gamma. sequence in cis. We demonstrate that binding of initiator protein to the seven strong, tandem binding sites in .gamma. increases binding of the protein at the very weak binding site present in ori .beta. by cooperativity at a distance. The .gamma.-.beta. interaction via the initiator results in a DNA loop, as revealed by the novel technique of cyclization enhancement and as confirmed by exonuclease III protection, electron microscopy, and chemical footprinting. The protein-mediated .gamma.-.beta. interaction in vitro suggests that the cooperative interaction of .gamma.-bound protein with the .beta. sequence by DNA looping is an early step in the initiation of DNA replication at the .beta. origin of R6K.