Reciprocal allostery arising from a bienzyme assembly controls aromatic amino acid biosynthesis in Prevotella nigrescens.
Reciprocal allostery arising from a bienzyme assembly controls aromatic amino acid biosynthesis in Prevotella nigrescens.
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DOI：
10.1016/j.jbc.2021.101038
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发表时间：
2021-09
期刊：
影响因子：
--
通讯作者：
Parker EJ
中科院分区：
文献类型：
--
作者：
Bai Y;Parker EJ
模块化蛋白质组装已被广泛报道为构建变构机器的机制。最近，已经在包含3-脱氧-d-阿拉伯庚酮糖酸-7-磷酸合酶（DAH 7 PS）和分支酸脱氢酶（CM）的双酶组装体中鉴定了独特的变构系统。这些酶分别催化细菌Prevotella nigrescens（PniDAH 7 PS）中芳香族氨基酸生物合成的第一和分支点反应。这两个不同的催化结构域之间的相互作用支持这种双功能酶内的功能相互依赖。CM催化反应的产物prephenate与CM结构域的结合与整体蛋白质构象的显著重排有关，该重排改变了结构域间的相互作用并变构地抑制DAH 7 PS活性。在这里，我们进一步研究了这种双功能酶所证明的复杂的变构通信。我们观察到在所有DAH 7 PS底物的存在下CM活性的变构活化。使用小角X射线散射（SAXS）实验，我们表明，在整体蛋白质构象和动力学的变化与不同的DAH 7 PS底物和变构抑制剂prephenate的存在。此外，我们已经确定了一个位于CM结构域的扩展螺旋间环，loopC 320-F333，作为结构域间结构和催化通信的关键片段。我们的研究结果表明，双功能酶PniDAH 7 PS包含一个相互变构系统之间的两个酶的部分，由于这种双向域间通信。这种布置允许复杂的反馈和前馈系统，用于通过连接芳香族氨基酸生物合成的起始点和分支点来控制途径通量。
Modular protein assembly has been widely reported as a mechanism for constructing allosteric machinery. Recently, a distinctive allosteric system has been identified in a bienzyme assembly comprising a 3-deoxy-d-arabino heptulosonate-7-phosphate synthase (DAH7PS) and chorismate mutase (CM). These enzymes catalyze the first and branch point reactions of aromatic amino acid biosynthesis in the bacterium Prevotella nigrescens (PniDAH7PS), respectively. The interactions between these two distinct catalytic domains support functional interreliance within this bifunctional enzyme. The binding of prephenate, the product of CM-catalyzed reaction, to the CM domain is associated with a striking rearrangement of overall protein conformation that alters the interdomain interactions and allosterically inhibits the DAH7PS activity. Here, we have further investigated the complex allosteric communication demonstrated by this bifunctional enzyme. We observed allosteric activation of CM activity in the presence of all DAH7PS substrates. Using small-angle X-ray scattering (SAXS) experiments, we show that changes in overall protein conformations and dynamics are associated with the presence of different DAH7PS substrates and the allosteric inhibitor prephenate. Furthermore, we have identified an extended interhelix loop located in CM domain, loopC320-F333, as a crucial segment for the interdomain structural and catalytic communications. Our results suggest that the dual-function enzyme PniDAH7PS contains a reciprocal allosteric system between the two enzymatic moieties as a result of this bidirectional interdomain communication. This arrangement allows for a complex feedback and feedforward system for control of pathway flux by connecting the initiation and branch point of aromatic amino acid biosynthesis.
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影响因子：
14.9
作者：
Mistry J;Chuguransky S;Williams L;Qureshi M;Salazar GA;Sonnhammer ELL;Tosatto SCE;Paladin L;Raj S;Richardson LJ;Finn RD;Bateman A
通讯作者：
Bateman A
影响因子：
4.8
作者：
Furdui, C;Zhou, L;Anderson, KS
通讯作者：
Anderson, KS
DOI：
10.1073/pnas.1717621115
发表时间：
2018-03-20
影响因子：
11.1
作者：
Fan, Yifei;Cross, Penelope J.;Parker, Emily J.
通讯作者：
Parker, Emily J.
影响因子：
6.1
作者：
Konarev, PV;Volkov, VV;Svergun, DI
通讯作者：
Svergun, DI
影响因子：
6.8
作者：
Lang, Eric J. M.;Cross, Penelope J.;Parker, Emily J.
通讯作者：
Parker, Emily J.