Characterization of TreR, the major regulator of the Escherichia coli trehalose system
Characterization of TreR, the major regulator of the Escherichia coli trehalose system
复制标题
DOI：
10.1074/jbc.272.20.13026
复制
发表时间：
1997-05-16
影响因子：
4.8
通讯作者：
Boos, W
中科院分区：
文献类型：
--
作者：
Horlacher, R;Boos, W
在低渗透压和高渗透压条件下，大肠杆菌对海藻糖的利用途径不同。低渗透压系统吸收海藻糖作为海藻糖B-磷酸，其水解为葡萄糖和葡萄糖6-磷酸，所涉及的酶的基因treB和treC形成由TreR控制的操纵子（由treR编码），该系统的阻遏物，海藻糖g-磷酸是其诱导物，我们克隆并测序了treR，该蛋白质含有315个氨基酸，分子量为34，508，纯化了TreR，并显示其作为二聚体海藻糖B-磷酸和海藻糖结合，K-d分别为10和280 μ M，蛋白质的构象彼此不同，与一种或另一种底物结合。蛋白酶处理从完整的蛋白质中去除DNA结合结构域，留下完整的二聚化结构域（29-kDa羧基末端片段）。核酸酶保护实验揭示了直接位于作为系统操纵子的treB的-35启动子序列上游的回文序列。
The pathway of trehalose utilization in Escherichia coli is different at low and high osmolarity. The low osmolarity system takes up trehalose as trehalose B-phosphate which is hydrolyzed to glucose and glucose 6-phosphate, treB and treC, the genes for the enzymes involved, form an operon that is controlled by TreR (encoded by treR), the repressor of the system, for which trehalose g-phosphate is the inducer, We have cloned and sequenced treR, The protein contains 315 amino acids with a molecular weight of 34,508, TreR was purified and shown to bind as a dimer trehalose B-phosphate and trehalose with a K-d of 10 and 280 mu M, respectively, The conformations of the protein differ from each other with either one or the other substrate-bound. Protease treatment removed the DNA-binding domain from the intact protein leaving the dimerization domain (a 29-kDa carboxyl-terminal fragment) intact, Nuclease protection experiments revealed a palindromic sequence located directly upstream of the -35 promoter sequence of treB that functions as the operator of the system.