Comparison of PsbQ and Psb27 in photosystem II provides insight into their roles.
Comparison of PsbQ and Psb27 in photosystem II provides insight into their roles.
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DOI：
10.1007/s11120-021-00888-2
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发表时间：
2022-05
影响因子：
3.7
通讯作者：
Brudvig, Gary W.
中科院分区：
文献类型：
--
作者：
Gisriel, Christopher J.;Brudvig, Gary W.
光系统 II (PSII) 在其含有高价无机 Mn4CaOx 的活性位点催化水的氧化。簇称为放氧复合物（OEC）。外在亚基通常用于保护 OEC 免受还原剂的影响并稳定结构，但光养生物之间存在外在亚基的多样性。最近的冷冻电子显微镜实验提供了具有各种外在亚基的 PSII 的新分子结构。我们重点关注与成熟 PSII 复合物结合的外在亚基 PsbQ，以及参与 PSII 生物发生的外在亚基 Psb27。 PsbQ 和 Psb27 具有相似的结合位点并具有四螺旋束三级结构，表明它们是相关的。在这里，我们使用序列比对、结构分析和结合模拟来比较来自不同生物体的 PsbQ 和 Psb27。我们没有发现任何证据表明 PsbQ 和 Psb27 相关，尽管它们的结构和结合位点相似。来自不同谱系的 PsbQ 同源物的进化差异很大，可能是由于它们与其他外在亚基的相互作用，而这些亚基本身在谱系之间表现出巨大的多样性。这可能会导致功能变化，例如计算出的结合能存在巨大差异。 Psb27 同源物通常表现出较小的差异，这可能是由于在 PSII 生物发生过程中维持其功能的某些残基的更强的进化选择，这与它们在生物体之间计算出的更相似的结合能一致。先前的实验不一致、低置信度结合模拟和最近的结构数据表明，Psb27 可能表现出灵活性，这可能是其活性的一个重要特征。该分析提供了对 PsbQ 和 Psb27 的功能和进化的深入了解，以及具有相似三级结构和可能发挥不同作用的结合位点的蛋白质的不寻常示例。
Photosystem II (PSII) catalyzes the oxidation of water at its active site that harbors a high-valent inorganic Mn4CaOx. cluster called the oxygen-evolving complex (OEC). Extrinsic subunits generally serve to protect the OEC from reductants and stabilize the structure, but diversity in the extrinsic subunits exists between phototrophs. Recent cryo-electron microscopy experiments have provided new molecular structures of PSII with varied extrinsic subunits. We focus on the extrinsic subunit PsbQ, that binds to the mature PSII complex, and on Psb27, an extrinsic subunit involved in PSII biogenesis. PsbQ and Psb27 share a similar binding site and have a four-helix bundle tertiary structure, suggesting they are related. Here, we use sequence alignments, structural analyses, and binding simulations to compare PsbQ and Psb27 from different organisms. We find no evidence that PsbQ and Psb27 are related despite their similar structures and binding sites. Evolutionary divergence within PsbQ homologs from different lineages is high, probably due to their interactions with other extrinsic subunits that themselves exhibit vast diversity between lineages. This may result in functional variation as exemplified by large differences in their calculated binding energies. Psb27 homologs generally exhibit less divergence, which may be due to stronger evolutionary selection for certain residues that maintain its function during PSII biogenesis and this is consistent with their more similar calculated binding energies between organisms. Previous experimental inconsistencies, low confidence binding simulations, and recent structural data suggest that Psb27 is likely to exhibit flexibility that may be an important characteristic of its activity. The analysis provides insight into the functions and evolution of PsbQ and Psb27, and an unusual example of proteins with similar tertiary structures and binding sites that probably serve different roles.
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影响因子：
14.9
作者：
Goujon M;McWilliam H;Li W;Valentin F;Squizzato S;Paern J;Lopez R
通讯作者：
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影响因子：
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作者：
Calderone, V;Trabucco, M;Zanotti, G
通讯作者：
Zanotti, G
DOI：
10.1016/j.jbc.2021.101424
发表时间：
2022-01
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Gisriel CJ;Shen G;Ho MY;Kurashov V;Flesher DA;Wang J;Armstrong WH;Golbeck JH;Gunner MR;Vinyard DJ;Debus RJ;Brudvig GW;Bryant DA
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作者：
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通讯作者：
Nowaczyk MM
影响因子：
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作者：
Allahverdiyeva, Yagut;Suorsa, Marjaana;Pesaresi, Paolo
通讯作者：
Pesaresi, Paolo