Rogov Vladimir V, Rogova Natalia Yu, Bernhard Frank, Koglin Alexander, Löhr Frank, Dötsch Volker
Institute of Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, JW Goethe-University, Frankfurt-am-Main, Germany.
J Mol Biol. 2006 Nov 17;364(1):68-79. doi: 10.1016/j.jmb.2006.07.052. Epub 2006 Jul 29.
The Rcs signalling pathway controls a variety of physiological functions like capsule synthesis, cell division or motility in prokaryotes. The Rcs regulation cascade, involving a multi-step phosphorelay between the two membrane-bound hybrid sensor kinases RcsC and RcsD and the global regulator RcsB, is, up to now, one of the most complicated regulatory systems in bacteria. To understand the structural basis of Rcs signal transduction, NMR spectroscopy was employed to determine the solution structure of the RcsC C terminus, possessing a phosphoreceiver domain (RcsC-PR), and a region previously described as a long linker between the histidine kinase domain of RcsC (RcsC-HK) and the RcsC-PR. We have found that the linker region comprises an independent structural domain of a new alpha/beta organization, which we named RcsC-ABL domain (Alpha/Beta/Loop). The ABL domain appears to be a conserved and unique structural element of RcsC-like kinases with no significant sequence homology to other proteins. The second domain of the C terminus, the RcsC-PR domain, represents a well-folded CheY-like phosphoreceiver domain with the central parallel beta-sheet covered with two alpha-helical layers on both sides. We have mapped the interaction of RcsC-ABL and RcsC-PR with the histidine phosphotransfer domain (HPt) of RcsD. In addition we have characterized the interaction with and the conformational effects of Mg2+ and the phosphorylation mimetic BeF(-)(3) on RcsC-ABL and RcsC-PR.
Rcs信号通路控制着原核生物中的多种生理功能，如荚膜合成、细胞分裂或运动性。Rcs调控级联涉及两个膜结合的杂合传感器激酶RcsC和RcsD与全局调节因子RcsB之间的多步磷酸化传递，截至目前，它是细菌中最复杂的调节系统之一。为了理解Rcs信号转导的结构基础，我们采用核磁共振光谱法来确定RcsC C末端的溶液结构，该结构包含一个磷酸受体结构域（RcsC-PR）以及先前被描述为RcsC组氨酸激酶结构域（RcsC-HK）与RcsC-PR之间长连接子的区域。我们发现该连接子区域包含一个新的α/β结构组织的独立结构域，我们将其命名为RcsC-ABL结构域（α/β/环）。ABL结构域似乎是RcsC样激酶的一个保守且独特的结构元件，与其他蛋白质没有明显的序列同源性。C末端的第二个结构域，即RcsC-PR结构域，代表一个折叠良好的CheY样磷酸受体结构域，其中心平行β折叠两侧覆盖着两个α螺旋层。我们绘制了RcsC-ABL和RcsC-PR与RcsD的组氨酸磷酸转移结构域（HPt）的相互作用。此外，我们还表征了Mg2+以及磷酸化模拟物BeF(-)(3)与RcsC-ABL和RcsC-PR的相互作用及其构象效应。
