DNase I footprinting shows three protected regions in the promoter of the rRNA genes of Xenopus laevis.
DNase I footprinting shows three protected regions in the promoter of the rRNA genes of Xenopus laevis.
复制标题
DNase I 足迹显示非洲爪蟾 rRNA 基因启动子中的三个受保护区域。
DOI：
10.1128/mcb.5.2.313-319.1985
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发表时间：
1985
影响因子：
5.3
通讯作者：
Reeder,RH
中科院分区：
文献类型：
--
作者：
Dunaway,M;Reeder,RH
从非洲爪蟾卵母细胞制备的提取物含有一种蛋白质，该蛋白质特异性地保护RNA聚合酶I启动子的三个不连续区域不被DNA酶I消化。保护区I，从核苷酸+15到核苷酸-10，跨越转录起始位点。保护区II相对于起始从核苷酸-70延伸到核苷酸-100，落入42个碱基对序列内，该序列与间隔区中启动子外部的60/81个碱基对重复元件同源。受保护的区域III位于区域II的上游，从核苷酸-120到核苷酸-140。所有这三个区域都与缺失研究中已知的对启动子功能重要的序列相关。通常保留区域I或区域II和III的缺失突变体。然而，III区的缺失减少了但并没有消除II区的足迹，这表明一种蛋白质与两个区域结合，或者与这些位点结合的蛋白质彼此相互作用。
Extracts prepared fromXenopus laevisoocytes contain a protein(s) which specifically protects three discrete regions of the RNA polymerase I promoter from digestion by DNase I. Protected region I, from nucleotide +15 to nucleotide −10, spans the site of transcription initiation. Protected region II extends from nucleotide −70 to nucleotide −100 relative to initiation, falling within a 42-base-pair sequence which is homologous to the 60/81-base-pair repeated elements which occur outside of the promoter in the spacer. Protected region III is upstream of region II, from nucleotide −120 to nucleotide −140. All three regions correlate with sequences known from deletion studies to be important for promoter function. Deletion mutants which retain either region I or regions II and III together footprint normally. Deletion of region III, however, reduces but does not eliminate footprinting on region II, suggesting either that one protein binds to both regions or that the proteins which bind to these sites interact with each other.