Avena sativa phototropin 1 light‐oxygen‐voltage 2 domain (AsLOV2) is a model protein of Per‐Arnt‐Sim (PAS) superfamily, characterized by conformational changes in response to external environmental stimuli. This conformational change begins with the unfolding of the N‐terminal A'α helix in the dark state followed by the unfolding of the C‐terminal Jα helix. The light state is characterized by the unfolded termini and the subsequent modifications in hydrogen bond patterns. In this photoreceptor, β‐sheets are identified as crucial components for mediating allosteric signal transmission between the two termini. Through combined experimental and computational investigations, the Hβ and Iβ strands are recognized as the most critical and influential β‐sheets in AsLOV2's allosteric mechanism. To elucidate the role of these β‐sheets, we introduced 13 distinct mutations (F490L, N492A, L493A, F494L, H495L, L496F, Q497A, R500A, F509L, Q513A, L514A, D515V, and T517V) and conducted comprehensive molecular dynamics simulations. In‐depth hydrogen bond analyses emphasized the role of two hydrogen bonds, Asn482‐Leu453 and Gln479‐Val520, in the observed distinct behaviors of L493A, L496F, Q497A, and D515V mutants. This illustrates the role of β‐sheets in the transmission of the allosteric signal upon the photoactivation of the light state.

中文翻译：

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β-折叠介导 AsLOV2 末端之间的构象变化和变构信号传递

燕麦向光素 1 光氧电压 2 结构域（作为LOV2）是 Per-Arnt-Sim (PAS) 超家族的模型蛋白，其特征是响应外部环境刺激而发生构象变化。这种构象变化始于 N 端 A' 的展开α黑暗状态下的螺旋，随后 C 末端 J 展开α螺旋。轻态的特征是末端未折叠以及氢键模式的后续修饰。在这个感光器中，β‐片材被认为是介导两个末端之间变构信号传递的关键成分。通过实验和计算相结合的研究，Hβ和我β股被认为是最关键和最有影响力的β‐表中作为LOV2的变构机制。为了阐明这些的作用β‐sheets 中，我们引入了 13 个不同的突变（F490L、N492A、L493A、F494L、H495L、L496F、Q497A、R500A、F509L、Q513A、L514A、D515V 和 T517V），并进行了全面的分子动力学模拟。深入的氢键分析强调了两个氢键 Asn482-Leu453 和 Gln479-Val520 在观察到的 L493A、L496F、Q497A 和 D515V 突变体的独特行为中的作用。这说明了作用β‐光态光激活时变构信号传输的片层。