Cyclic AMP-dependent functional forms of cyclic AMP receptor protein from Vibrio cholerae
Cyclic AMP-dependent functional forms of cyclic AMP receptor protein from Vibrio cholerae
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DOI：
10.1016/j.abb.2006.01.001
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发表时间：
2006-03-01
影响因子：
3.9
通讯作者：
Parrack, P
中科院分区：
文献类型：
--
作者：
Chattopadhyay, R;Parrack, P
来自大肠杆菌的环AMP受体蛋白（CRP）参与了许多基因和操纵子的转录调控，通过结合启动子上游的特定位点起作用。CRP还结合环AMP (cAMP)，这种结合引起CRP构象变化，是其活性的必要条件。据报道，大肠杆菌CRP的构象和生物活性存在cAMP依赖性变异，cAMP-CRP复合物在高cAMP浓度下形成，类似于未络合的载脂蛋白CRP。来自霍乱弧菌的CRP与大肠杆菌蛋白具有95%的序列同源性，在毒力基因表达调控中起重要作用。我们纯化并鉴定了霍乱弧菌CRP，并研究了其转录激活特性作为cAMP浓度增加的功能。观察到cAMP水平的双相依赖性，类似于大肠杆菌CRP的发现。这些结果对霍乱弧菌中cAMP-CRP依赖启动子调控的意义已经进行了讨论。(c) 2006爱思唯尔公司版权所有。
The cyclic AMP receptor protein (CRP) from Escherichia coli, involved in the transcriptional regulation of a number of genes and operons, works by binding to specific sites upstream of promoters. CRP also binds cyclic AMP (cAMP), and this binding, which causes conformational changes in CRP, is mandatory for its activity. A cAMP-dependent variation in the conformation as well as biological activity of E coli CRP has been reported, with the cAMP-CRP complex formed at high cAMP concentrations resembling the uncomplexed apoprotein CRP. CRP from Vibrio cholerae, which plays an important role in the regulation of virulence gene expression, has a 95% sequence identity with the E coli protein. We have purified and characterized V. cholerae CRP and studied its transcription activation properties as a function of increasing cAMP concentrations. A biphasic dependence on cAMP levels was observed, similar to that found for E.coli CRP. The implications of these results on regulation of cAMP-CRP dependent promoters in V cholerae has been discussed. (c) 2006 Elsevier Inc. All rights reserved.