DNA RECOGNITION BY THE NIT2 NITROGEN REGULATORY PROTEIN - IMPORTANCE OF THE NUMBER, SPACING, AND ORIENTATION OF GATA CORE ELEMENTS AND THEIR FLANKING SEQUENCES UPON NIT2 BINDING
DNA RECOGNITION BY THE NIT2 NITROGEN REGULATORY PROTEIN - IMPORTANCE OF THE NUMBER, SPACING, AND ORIENTATION OF GATA CORE ELEMENTS AND THEIR FLANKING SEQUENCES UPON NIT2 BINDING
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DOI：
10.1021/bi00168a024
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发表时间：
1994-01-18
期刊：
影响因子：
2.9
通讯作者：
MARZLUF, GA
中科院分区：
文献类型：
--
作者：
CHIANG, TY;MARZLUF, GA
NIT 2是粗糙脉孢菌中的一种全局性正性调节蛋白，激活氮调节回路中一系列不相关结构基因的表达。除了存在至少两个拷贝的加塔核心序列之外，nit-3、alc和lao基因的启动子区中的NIT 2结合位点在序列背景中非常不同。仅改变两个紧密间隔的加塔核心元件之一的单个核苷酸就可以消除NIT 2结合，表明它们对NIT 2结合的重要性。研究了改变成对加塔元件的数量、方向或间距的影响以及5 '和3'侧翼序列对NIT 2结合的重要性。NIT 2-β GAL融合蛋白的强结合位点似乎含有至少两个加塔元件，其可以具有不同的间距，但必须在彼此的一定有效距离内，约30 bp。令人惊讶的是，加塔元件及其侧翼序列的取向对NIT 2结合仅具有适度的影响。
NIT2, a global positive-acting regulatory protein in Neurospora crassa, activates the expression of a series of unlinked structural genes in the nitrogen regulation circuit. NIT2 binding sites in the promoter region of the nit-3, alc, and lao genes are very different in sequence context except for the presence of at least two copies of a GATA core sequence. Changing a single nucleotide of only one of two closely spaced GATA core elements abolished NIT2 binding, demonstrating their importance for NIT2 binding. The effect of altering the number, orientation, or spacing of paired GATA elements and the importance of 5'- and 3'-flanking sequences upon NIT2 binding were examined. Strong binding sites for a NIT2-betaGAL fusion protein appear to contain at least two GATA elements, which can have varied spacing but must be within a certain effective distance, approximately 30 bp, of each other. Surprisingly, the orientation of GATA elements and their flanking sequences have only modest effects upon NIT2 binding.