NMR structure of the pseudo-receiver domain of CikA
NMR structure of the pseudo-receiver domain of CikA
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DOI：
10.1110/ps.062532007
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发表时间：
2007-03-01
期刊：
影响因子：
8
通讯作者：
LiWang, Andy
中科院分区：
文献类型：
--
作者：
Gao, Tiyu;Zhang, Xiaofan;LiWang, Andy
昼夜节律输入激酶(Cika)是向长聚球藻生物钟提供环境信息的途径中的一个主要元件。Cika是一个由754个残基组成的多肽，具有三个可识别的结构域：GAF、组氨酸蛋白激酶和受体样蛋白。Cika的后一个结构域缺乏真正受体结构域的保守的接受磷的天冬氨酸残基，因此是一个假受体(PSR)。最近的研究表明，PSR结构域(1)减弱了CIKA的自身激酶活性，(2)是将CIKA定位到细胞极点所必需的，(3)是在苯二酚类似物2，5-dibromo-3methyl-6-isopropyl-p-benzoquinone(DBMIB)存在下，CIKA失稳所必需的。这里给出了Cika的PSR结构域CikAPsR的解结构。PSR结构域与Cika的HPK部分之间的相互作用模型为PSR结构域如何减弱Cika的自激酶活性提供了一个潜在的解释。最后，这里显示了CikAPsR上一个可能的苯醌结合表面。
The circadian input kinase (CikA) is a major element of the pathway that provides environmental information to the circadian clock of the cyanobacterium Synechococcus elongatus. CikA is a polypeptide of 754 residues and has three recognizable domains: GAF, histidine protein kinase, and receiver-like. This latter domain of CikA lacks the conserved phospho-accepting aspartyl residue of bona fide receiver domains and is thus a pseudo-receiver (PsR). Recently, it was shown that the PsR domain (1) attenuates the autokinase activity of CikA, (2) is necessary to localize CikA to the cell pole, and (3) is necessary for the destabilization of CikA in the presence of the quinone analog 2,5-dibromo-3methyl-6-isopropyl-p-benzoquinone (DBMIB). The solution structure of the PsR domain of CikA, CikAPsR, is presented here. A model of the interaction between the PsR domain and HPK portion of CikA provides a potential explanation for how the PsR domain attenuates the autokinase activity of CikA. Finally, a likely quinone-binding surface on CikAPsR is shown here.