The NMR solution structure of BeF3--activated Spo0F reveals the conformational switch in a phosphorelay system
The NMR solution structure of BeF3--activated Spo0F reveals the conformational switch in a phosphorelay system
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DOI：
10.1016/s0022-2836(03)00733-2
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发表时间：
2003-08-01
影响因子：
5.6
通讯作者：
Kern, D
中科院分区：
文献类型：
--
作者：
Gardino, AK;Volkman, BF;Kern, D
由一个组氨酸-天冬氨酸磷酸转移模块组成的双组分系统是细菌中的主要信号通路，最近在几种真核生物中也被发现。两个或多个组氨酸-天冬氨酸基序的串联连接形成了复杂的磷酸继电器。虽然简单的双组分系统的响应调节器在结构上分为非活性和活性两种形式，但我们在这里讨论的问题是，来自磷继电器的响应调节器是否具有明显的激活结构基础。我们报道了BeF3激活的Spo0F的核磁共振溶液结构，这是磷继电器在激活状态下的第一个响应调节器结构。在简单的双组分体系中发现了构象变化的区域。此外，由于BeF3-的激活，位于公共活化面相反侧的螺旋1向下移动了半个螺旋。螺旋1的构象变化可以通过磷酸转移到第二组氨酸激酶Spo0B的不同功能来合理化，因为已知螺旋1直接与Spo0B和磷酸酶RapB相互作用。Spo0F中结构重排的鉴定支持了在先前关于Spo0F的核磁共振动力学研究的基础上提出的在磷酸化前的非活性状态和活性状态之间存在预先存在的平衡的假说。改变既有的平衡很可能是应对监管机构的一个普遍特征。(C)2003爱思唯尔有限公司。保留所有权利。
Two-component systems, which are comprised of a single histidine-aspartate phosphotransfer module, are the dominant signaling pathways in bacteria and have recently been identified in several eukaryotic organisms as well. A tandem connection of two or more histidine-aspartate motifs forms complex phosphorelays. While response regulators from simple two-component systems have been characterized structurally in their inactive and active forms, we address here the question of whether a response regulator from a phosphorelay has a distinct structural basis of activation. We report the NMR solution structure of BeF3--activated Spo0F, the first structure of a response regulator from a phosphorelay in its activated state. Conformational changes were found in regions previously identified to change in simple two-component systems. In addition, a downward shift by half a helical turn in helix 1, located on the opposite side of the common activation surface, was observed as a consequence of BeF3- activation. Conformational changes in helix 1 can be rationalized by the distinct function of phosphoryl transfer to the second histidine kinase, Spo0B, because helix 1 is known to interact directly with Spo0B and the phosphatase RapB. The identification of structural rearrangements in Spo0F supports the hypothesis of a pre-existing equilibrium between the inactive and active state prior to phosphorylation that was suggested on the basis of previous NMR dynamics studies on Spo0F. A shift of a pre-existing equilibrium is likely a general feature of response regulators. (C) 2003 Elsevier Ltd. All rights reserved.