Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Laboratório de Tecnologia Biomolecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.
Proteins. 2023 Jul;91(7):944-955. doi: 10.1002/prot.26481. Epub 2023 Mar 6.
Intrinsically disordered proteins (IDPs) have numerous dynamic conformations. Given the difficulties in tracking temporarily folded states of this kind of protein, methods such as molecular modeling and molecular dynamics (MD) simulations make the process less costly, less laborious, and more detailed. Few plant IDPs have been characterized so far, such as proteins from the Abscisic acid, Stress and Ripening (ASR) family. The present work applied, for the first time, the two above-mentioned tools to test the feasibility of determining a three-dimensional transition model of OsASR5 and to investigate the relationship between OsASR5 and zinc. We found that one of OsASR5's conformers contains α-helices, turns, and loops and that the metal binding resulted in a predominance of α-helix. This stability is possibly imperative for the transcription factor activity. The promoter region of a sugar transporter was chosen to test this hypothesis and free energy calculations showed how the ion is mandatory for this complex formation. The results produced here aim to clarify which conformation the protein in the bound state assumes and which residues are involved in the process, besides developing the understanding of how the flexibility of these proteins can contribute to the response to environmental stresses.
无规卷曲蛋白质（IDPs）具有许多动态构象。鉴于跟踪此类蛋白质的暂时折叠状态存在困难，分子建模和分子动力学（MD）模拟等方法使该过程的成本更低、劳动强度更小且更详细。到目前为止，只有少数植物 IDPs 得到了表征，例如来自脱落酸、应激和成熟（ASR）家族的蛋白质。本研究首次应用上述两种工具来测试确定 OsASR5 三维过渡模型的可行性，并研究 OsASR5 与锌之间的关系。我们发现 OsASR5 的构象之一包含α-螺旋、转角和环，金属结合导致α-螺旋占优势。这种稳定性对于转录因子活性可能是必要的。选择糖转运蛋白的启动子区域来检验这一假设，自由能计算表明离子对于这种复合物形成是必需的。这里产生的结果旨在阐明结合状态下蛋白质的构象以及参与该过程的残基，此外还阐明了这些蛋白质的灵活性如何有助于对环境胁迫的响应。
