DNA-protein interactions at the S.cerevisiae α2 operator in vivo
DNA-protein interactions at the S.cerevisiae α2 operator in vivo
复制标题
体内酿酒酵母α2操纵子的DNA-蛋白质相互作用
DOI：
10.1093/nar/21.14.3295
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发表时间：
1993
影响因子：
14.9
通讯作者：
R. Simpson
中科院分区：
文献类型：
--
作者：
Michael R. Murphy;M. Shimizu;S. Roth;A. Dranginis;R. Simpson
需要两种同源二聚体蛋白α 2和MCM 1来抑制单倍体酵母α细胞中α细胞类型特异性基因的转录。其他人对这些蛋白质与操纵基因DNA相互作用的体外研究表明，MCM 1与31 bp操纵基因的中部结合，α 2与末端结合。我们以前已经表明，α 2组织染色质结构相邻的运营商，在α 2阻遏物的存在下，一个精确定位的核小体毗邻运营商在微型染色体和基因组。我们目前在体内足迹的证据一致的经营者MCM 1在α-和α-细胞和α 2阻遏物在α-细胞的占用。有趣的是，我们的体内结果与以前的体外工作在细节上不同。在对比广泛的块试剂的可及性DNA的因素在体外，我们发现一种模式的链特异性保护或增强的反应性在体内。体内结果与关于α细胞特异性基因的转录调控的遗传数据一致，并证实了其他人的晶体学数据。
Two homodimeric proteins, alpha 2 and MCM1, are required to repress transcription of a-cell type specific genes in haploid yeast alpha-cells. In vitro studies by others of the interactions of these proteins with operator DNA have suggested that MCM1 binds to the middle and alpha 2 to the ends of the 31 bp operator. We have previously shown that alpha 2 organizes chromatin structure adjacent to the operator; in the presence of alpha 2 repressor, a precisely positioned nucleosome abuts the operator in both minichromosomes and the genome. We present in vivo footprinting evidence consistent with occupancy of the operator by MCM1 in both a- and alpha-cells and by alpha 2 repressor in alpha-cells. Interestingly, our in vivo results differ from previous in vitro work in detail. In contrast to the broad block of reagent accessibility to DNA by the factors seen in vitro, we find a pattern of strand-specific protection or augmented reactivity in vivo. The in vivo results are consistent with genetic data concerning transcriptional regulation of a-cell specific genes and corroborate the crystallographic data of others.