Two-state allosteric behavior in a single-domain signaling protein
Two-state allosteric behavior in a single-domain signaling protein
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DOI：
10.1126/science.291.5512.2429
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发表时间：
2001-03-23
期刊：
影响因子：
56.9
通讯作者：
Kern, D
中科院分区：
文献类型：
--
作者：
Volkman, BF;Lipson, D;Kern, D
蛋白质的作用通常是根据静态结构来讨论的，但功能需要运动。我们发现信号蛋白 NtrC 的磷酸化驱动激活与微秒时间尺度的主链动力学之间存在很强的相关性。利用核磁共振弛豫，我们表征了 NtrC 在三种功能状态下的运动：非磷酸化（非活性）、磷酸化（活性）和部分活性突变体。这些动态表明非活性和活性构象之间的交换。这两种状态都存在于未磷酸化的 NtrC 中，磷酸化使平衡向活性物质方向移动。这些结果支持两种预先存在的构象之间的动态群体转变作为激活的潜在机制。
Protein actions are usually discussed in terms of static structures, but function requires motion. We find a strong correlation between phosphorylation-driven activation of the signaling protein NtrC and microsecond time-scale backbone dynamics. Using nuclear magnetic resonance relaxation, we characterized the motions of NtrC in three functional states: unphosphorylated (inactive), phosphorylated (active), and a partially active mutant. These dynamics are indicative of exchange between inactive and active conformations. Both states are populated in unphosphorylated NtrC, and phosphorylation shifts the equilibrium toward the active species. These results support a dynamic population shift between two preexisting conformations as the underlying mechanism of activation.