The REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, DK-2200, Denmark.
Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, DK-2200, Denmark.
Commun Biol. 2023 Jan 18;6(1):63. doi: 10.1038/s42003-023-04445-6.
Transcription depends on complex networks, where folded hub proteins interact with intrinsically disordered transcription factors undergoing coupled folding and binding. For this, local residual structure, a prototypical feature of intrinsic disorder, is key. Here, we dissect the unexplored functional potential of residual structure by comparing structure, kinetics, and thermodynamics within the model system constituted of the DREB2A transcription factor interacting with the αα-hub RCD1-RST. To maintain biological relevance, we developed an orthogonal evolutionary approach for the design of variants with varying amounts of structure. Biophysical analysis revealed a correlation between the amount of residual helical structure and binding affinity, manifested in altered complex lifetime due to changed dissociation rate constants. It also showed a correlation between helical structure in free and bound DREB2A variants. Overall, this study demonstrated how evolution can balance and fine-tune residual structure to regulate complexes in coupled folding and binding, potentially affecting transcription factor competition.
转录依赖于复杂的网络，其中折叠的枢纽蛋白与经历偶联折叠和结合的固有无序转录因子相互作用。为此，局部残基结构（固有无序的典型特征）是关键。在这里，我们通过比较由 DREB2A 转录因子与 αα 枢纽 RCD1-RST 相互作用构成的模型系统中的结构、动力学和热力学，来剖析残基结构未被探索的功能潜力。为了保持生物学相关性，我们开发了一种正交进化方法来设计具有不同结构含量的变体。生物物理分析表明，残基螺旋结构的含量与结合亲和力之间存在相关性，这表现为由于解离速率常数的变化，复合物的寿命发生改变。它还显示了自由和结合的 DREB2A 变体中螺旋结构之间的相关性。总的来说，这项研究表明了进化如何平衡和微调残基结构以调节偶联折叠和结合的复合物，这可能会影响转录因子的竞争。
