Crystal structure of a cyanobacterial phytochrome response regulator
Crystal structure of a cyanobacterial phytochrome response regulator
复制标题
DOI：
10.1110/ps.39102
复制
发表时间：
2002-03-01
期刊：
影响因子：
8
通讯作者：
Eom, SH
中科院分区：
文献类型：
--
作者：
Im, YJ;Rho, SH;Eom, SH
双组分信号转导途径广泛存在于原核生物、真菌、霉菌和一些植物中，涉及一个复杂的磷接力级联。Rcp1是一个双组分系统中的磷酸盐接收器模块，通过蓝细菌光敏色素Cph1控制蓝细菌的光响应，该系统识别Rcp1并将其磷酸化基团转移到响应光的天冬氨酸残基上。本文描述了Rcp1的晶体结构，在1.9埃的分辨率下，晶体学r因子细化到18.8%。该结构揭示了一种紧密结合的血二聚体，其单体由双缠绕的五链平行β -片组成，形成与其他反应调节因子（例如趋化蛋白CheY）的n端激活子结构域同源的单结构域蛋白。Rcp1的三维结构似乎与磷酸盐受体蛋白的保守活化机制一致。尽管在这种情况下，其调节结构域的c端在磷酸化后发生结构变化，有助于二聚化界面。磷酸化诱导二聚体界面构象变化的残基的参与表明，Rcp1的二聚化可能受到磷酸化的调控，从而影响Rcp1与下游靶分子的相互作用。
The two-component signal transduction pathway widespread in prokaryotes, fungi, molds, and some plants involves an elaborate phosphorelay cascade. Rcp1 is the phosphate receiver module in a two-component system controlling the light response of cyanobacteria Synechocystis sp. via cyanobacterial phytochrome Cph1, which recognizes Rcp1 and transfers its phosphoryl group to an aspartate residue in response to light. Here we describe the crystal structure of Rcp1 refined to a crystallographic R-factor of 18.8% at a resolution of 1.9 Angstrom. The structure reveals a tightly associated hemodimer with monomers comprised of doubly wound five-stranded parallel beta-sheets forming a single-domain protein homologous with the N-terminal activator domain of other response regulators (e.g., chemotaxis protein CheY). The three-dimensional structure of Rcp1 appears consistent with the conserved activation mechanism of phosphate receiver proteins. although in this case, the C-terminal half of its regulatory domain, which undergoes structural changes upon phosphorylation, contributes to the dimerization interface. The involvement of the residues undergoing phosphorylation-induced conformational changes at the dimeric interface suggests that dimerization of Rcp1 may be regulated by phosphorylation, which could affect the interaction of Rcp1 with downstream target molecules.