Disassembly of the ring‐type decameric structure of peroxiredoxin from Aeropyrum pernix K1 by amino acid mutation
Disassembly of the ring‐type decameric structure of peroxiredoxin from Aeropyrum pernix K1 by amino acid mutation
复制标题
通过氨基酸突变分解来自 Aeropyrum pernix K1 的过氧化还原蛋白的环型十聚体结构
DOI：
10.1002/pro.3837
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发表时间：
2020
期刊：
影响因子：
8
通讯作者：
Nakamura Tsutomu
中科院分区：
文献类型：
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作者：
Himiyama Tomoki;Nakamura Tsutomu
来自Aeropyrum pernixK1的过氧化还蛋白(ApPrx)的四级结构是一个十聚体，其中五个同源二聚体通过疏水相互作用组装成一个五角环。在这项研究中，我们确定了ApPrx的氨基酸(AA)残基，这是使用AA突变形成十聚体的关键。将半胱氨酸残基全部突变为丝氨酸的ApPrx0Cys突变体作为模型蛋白，消除半胱氨酸氧化还原状态对其组装行为的影响。ApPrx0Cys的每个同源二聚体之间的边界包含形成疏水相互作用的特征芳香族AA残基：F46、F80、W88、W210和W211。我们发现，F46、F80或W210的一个突变为丙氨酸，将ApPrx0Cys的解聚体完全分解为同源二聚体，这一点通过凝胶过滤层析和动态光散射测量得到了澄清。与ApPrx0Cys相比，F46A、F80A和W210A突变体只缺少一个芳香环，表明该组装对蛋白质的表面结构非常敏感。X射线结构揭示了ApPrx十聚体的两种解离机制：同源二聚体之间疏水性的丧失和臂结构域的翻转。本研究中靶向的AA残基在环型PRX蛋白中非常保守，表明这些残基在组装中的重要性。这项研究通过一个简单的AA突变证明了过氧化还蛋白组装的敏感性和可变性。
The quaternary structure of peroxiredoxin fromAeropyrum pernixK1 (ApPrx) is a decamer, in which five homodimers are assembled in a pentagonal ring through hydrophobic interactions. In this study, we determined the amino acid (AA) residues of ApPrx crucial for forming the decamer using AA mutations. The ApPrx0Cys mutant, wherein all cysteine residues were mutated to serine, was prepared as a model protein to remove the influence of the redox states of the cysteines on its assembling behavior. The boundary between each homodimer of ApPrx0Cys contains characteristic aromatic AA residues forming hydrophobic interactions: F46, F80, W88, W210, and W211. We found that a single mutation of F46, F80, or W210 to alanine completely disassembled the ApPrx0Cys decamer to homodimers, which was clarified by gel‐filtration chromatography and dynamic light scattering measurements. F46A, F80A, and W210A mutants lacked only one aromatic ring compared with ApPrx0Cys, indicating that the assembly is very sensitive to the surface structure of the protein. X‐ray structures revealed two mechanisms of disassembly of the ApPrx decamer: loss of hydrophobicity between homodimers and flip of the arm domain. The AA residues targeted in this study are well conserved in ring‐type Prx proteins, suggesting the importance of these residues in the assembly. This study demonstrates the sensitivity and modifiability of peroxiredoxin assembly by a simple AA mutation.