Modeling the cAMP-induced allosteric transition using the crystal structure of CAP-cAMP at 2.1 Å resolution
Modeling the cAMP-induced allosteric transition using the crystal structure of CAP-cAMP at 2.1 Å resolution
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DOI：
10.1006/jmbi.2000.4231
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发表时间：
2000-12-15
影响因子：
5.6
通讯作者：
Steitz, TA
中科院分区：
文献类型：
--
作者：
Passner, JM;Schultz, SC;Steitz, TA
大肠杆菌分解代谢物基因激活蛋白（CAP）通过与环腺苷酸（cAMP）结合产生变构转换后，特异性地与DNA结合并激活转录。CAP-cAMP复合物的三维晶体结构已在2.1埃分辨率下得到细化，从而能够更好地评估CAP表型的结构基础、cAMP与CAP的相互作用以及水结构所起的作用。CAP的突变分析的审查连同额外的结构信息，这里提出了一个可能的机制cAMP诱导的变构所需的DNA结合和转录激活。我们假设cAMP结合可以重新定向卷曲螺旋C-螺旋，这提供了大部分的二聚体接口，从而改变CAP二聚体的DNA结合域的相对位置。此外，cAMP结合可通过位于cAMP上的由β链4和5组成的瓣引起CAP的DNA结合和cAMP结合结构域的进一步重排。(C)北京大学出版社.
After an allosteric transition produced by the binding of cyclic AMP (cAMP), the Escherichia coli catabolite gene activator protein (CAP) binds DNA specifically and activates transcription. The three-dimensional crystal structure of the CAP-cAMP complex has been refined at 2.1 Angstrom resolution, thus enabling a better evaluation of the structural basis for CAP phenotypes, the interactions of cAMP with CAP and the roles played by water structure. A review of mutational analysis of CAP together with the additional structural information presented here suggests a possible mechanism for the cAMP-induced allostery required for DNA binding and transcriptional activation. We hypothesize that cAMP binding may reorient the coiled-coil C-helices, which provide most of the dimer interface, thereby altering the relative positions of the DNA-binding domains of the CAP dimer. Additionally, cAMP binding may cause a further rearrangement of the DNA-binding and cAMP-binding domains of CAP via a flap consisting of beta -strands 4 and 5 which lies over the cAMP. (C) 2000 Academic Press.