Abstract:
The Light-oxygen-voltage-sensing domain (LOV) superfamily, found in enzymes and signal transduction proteins, plays a crucial role in converting light signals into structural signals, mediating various biological mechanisms. While time-resolved spectroscopic studies have revealed the dynamics of the LOV-domain chromophore\'s electronic structures, understanding the structural changes in the protein moiety, particularly regarding light-induced dimerization, remains challenging. Here, we utilize time-resolved X-ray liquidography to capture the light-induced dimerization of Avena sativa LOV2. Our analysis unveils that dimerization occurs within milliseconds after the unfolding of the A\'α and Jα helices in the microsecond time range. Notably, our findings suggest that protein-protein interactions (PPIs) among the β-scaffolds, mediated by helix unfolding, play a key role in dimerization. In this work, we offer structural insights into the dimerization of LOV2 proteins following structural changes in the A\'α and Jα helices, as well as mechanistic insights into the protein-protein association process driven by PPIs.
摘要:
光氧电压感应域(LOV)超家族,在酶和信号转导蛋白中发现,在将光信号转换为结构信号中起着至关重要的作用,介导各种生物学机制。虽然时间分辨光谱研究揭示了LOV域发色团电子结构的动力学,了解蛋白质部分的结构变化,特别是关于光诱导的二聚化,仍然具有挑战性。这里,我们利用时间分辨X射线液相成像来捕获AvenasativaLOV2的光诱导二聚化。我们的分析揭示了在微秒时间范围内A\'α和Jα螺旋展开后的毫秒内发生二聚化。值得注意的是,我们的发现表明,β-支架之间的蛋白质-蛋白质相互作用(PPI),由螺旋展开介导,在二聚化中起关键作用。在这项工作中,我们提供了对LOV2蛋白在A\'α和Jα螺旋结构变化后的二聚化的结构见解,以及对PPI驱动的蛋白质-蛋白质缔合过程的机械见解。