Critical Assessment of Protein Cross-Linking and Molecular Docking: An Updated Model for the Interaction Between Photosystem II and Psb27.
Critical Assessment of Protein Cross-Linking and Molecular Docking: An Updated Model for the Interaction Between Photosystem II and Psb27.
复制标题
DOI：
10.3389/fpls.2016.00157
复制
发表时间：
2016
影响因子：
5.6
通讯作者：
Nowaczyk MM
中科院分区：
文献类型：
--
作者：
Cormann KU;Möller M;Nowaczyk MM
光系统 II (PSII) 是一种大型膜蛋白复合物，由约 20 个亚基和各种辅助因子组成，介导光驱动的水氧化和质体醌还原，是位于蓝藻、藻类和植物类囊体膜中的光合电子传递链的一部分。 PSII 的逐步组装受到众多辅助蛋白的指导和促进，这些辅助蛋白在此时空过程中发挥特定作用。 Psb27 是一种位于类囊体腔内的小蛋白，似乎与参与 Mn4CaO5 簇组装的中间 PSII 复合物相关。它在 PSII 中间体上的精确结合位置仍然难以捉摸，因为之前将 Psb27 在 PSII 上定位的方法产生了矛盾的结果。这是我们对以前使用的方法进行严格评估并开发改进的分析流程的动机。参考 PSII 晶体结构，对化学交联和质谱 (CX-MS) 与同位素编码交联剂的组合进行了改进和验证。基于连接 Psb27-K91 和 CP43-K381 的交联，Psb27 位于邻近 CP43 大腔域的 PSII 表面上。通过表面等离振子共振 (SPR) 光谱检测到 Psb27 与 CP47 以及 D1 和 D2 的 C 末端关联的其他接触。该信息用于模拟 Psb27 与成熟复合物中 PsbV 占据的区域中的 PSII 表面的结合。
Photosystem II (PSII) is a large membrane-protein complex composed of about 20 subunits and various cofactors, which mediates the light-driven oxidation of water and reduction of plastoquinone, and is part of the photosynthetic electron transfer chain that is localized in the thylakoid membrane of cyanobacteria, algae, and plants. The stepwise assembly of PSII is guided and facilitated by numerous auxiliary proteins that play specific roles in this spatiotemporal process. Psb27, a small protein localized in the thylakoid lumen, appears to associate with an intermediate PSII complex that is involved in assembly of the Mn4CaO5 cluster. Its precise binding position on the PSII intermediate remains elusive, as previous approaches to the localization of Psb27 on PSII have yielded contradictory results. This was our motivation for a critical assessment of previously used methods and the development of an improved analysis pipeline. The combination of chemical cross-linking and mass spectrometry (CX-MS) with isotope-coded cross-linkers was refined and validated with reference to the PSII crystal structure. Psb27 was localized on the PSII surface adjacent to the large lumenal domain of CP43 on the basis of a cross-link connecting Psb27-K91 to CP43-K381. Additional contacts associating Psb27 with CP47 and the C-termini of D1 and D2 were detected by surface plasmon resonance (SPR) spectroscopy. This information was used to model the binding of Psb27 to the PSII surface in a region that is occupied by PsbV in the mature complex.