IN ORGANELLO FOOTPRINT ANALYSIS OF HUMAN MITOCHONDRIAL-DNA - HUMAN MITOCHONDRIAL TRANSCRIPTION FACTOR-A INTERACTIONS AT THE ORIGIN OF REPLICATION
IN ORGANELLO FOOTPRINT ANALYSIS OF HUMAN MITOCHONDRIAL-DNA - HUMAN MITOCHONDRIAL TRANSCRIPTION FACTOR-A INTERACTIONS AT THE ORIGIN OF REPLICATION
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DOI：
10.1128/mcb.14.12.7717
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发表时间：
1994-12-01
影响因子：
5.3
通讯作者：
HAUSWIRTH, WW
中科院分区：
文献类型：
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作者：
GHIVIZZANI, SC;MADSEN, CS;HAUSWIRTH, WW
利用细胞器足迹分析，我们证明在人胎盘线粒体中，蛋白质-DNA以规则的阶段性间隔结合在一个500bp的区域，该区域包括D-loop DNA起始区和两个启动子区域。与体外DNase I保护研究相比，研究表明这种蛋白质与DNA的相互作用是由于人线粒体转录因子A(h-mtTFA)的非序列特异性结合所致。由于h-mtTFA可以弯曲和包裹DNA，就像它的酵母对应物ABF2一样，h-mtTFA的主要功能似乎是在体内对线粒体DNA控制区进行特异性包装。蛋白质结合的间隔与RNA起始点和突出的D-loop DNA 5‘末端的间距一致，表明阶段性h-mtTFA结合在定义转录和H链DNA复制起点方面发挥了作用。利用纯化的h-mtTFA，在细胞器和体外，在保守序列块1的人类同源物中也观察到显著的蛋白质-DNA相互作用。
Using in organello footprint analysis, we demonstrate that within human placental mitochondria there is a high level of protein-DNA binding at regularly phased intervals throughout a 500-bp region encompassing the D-loop DNA origins and two promoter regions. Comparison with in vitro DNase I protection studies indicates that this protein-DNA interaction is due to non-sequence-specific binding by human mitochondrial transcription factor A (h-mtTFA). Since h-mtTFA can bend and wrap DNA, like its yeast counterpart ABF2, a primary function of h-mtTFA appears to be specific packaging of the mitochondrial DNA control region in vivo. Intervals of protein binding coincide with the spacing of the RNA start sites and prominent D-loop DNA 5' ends, suggesting a role for phased h-mtTFA binding in defining transcription and H-strand DNA replication origins. Significant protein-DNA interaction was also observed within the human homolog of conserved sequence block 1, both in organello and in vitro, using purified h-mtTFA.