Beyond the coupled distortion model: structural analysis of the single domain cupredoxin AcoP, a green mononuclear copper centre with original features.
Beyond the coupled distortion model: structural analysis of the single domain cupredoxin AcoP, a green mononuclear copper centre with original features.
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DOI：
10.1039/d3dt03372d
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发表时间：
2024-01-23
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铜氧还蛋白是一种广泛存在的铜结合蛋白，具有典型的Greek-key β桶折叠。它们通常被描述为依赖于由折叠多肽提供的四个配体配位的T1铜中心的电子载体。新的铜氧还蛋白的发现证明了这个家族的高度多样性，在铜结合配体、铜中心几何形状、氧化还原电位以及生物学功能方面具有变化。AcoP是属于嗜酸性细菌Acidithiobacillus ferrooxidans的铁呼吸链的周质铜氧还蛋白。AcoP呈现出原始特征，包括对酸性pH的高耐受性和高氧化还原电位的受约束的绿色型铜中心。为了了解AcoP的独特性质，我们对野生型AcoP和两种Cu配体突变体（H166 A和M171 A）进行了结构和生物物理表征。晶体结构，包括1.65 μ m分辨率的天然还原AcoP，揭示了典型的铜氧还蛋白折叠。延伸的循环的存在下，从来没有观察到在以前的特点cupredoxins，可能占AcoP与生理合作伙伴的相互作用。铜配体的距离，由X-射线衍射和EXAFS测定，表明AcoP金属中心似乎同时存在T1和T1.5的功能，反过来表明AcoP可能不适合耦合畸变模型。两个AcoP突变体的晶体结构证实AcoP的活性中心是高度受限的。与其他已知结构的cupredoxins的比较分析表明，在AcoP的第二个协调领域可能是一个重要的决定因素，由于存在广泛的氢键网络的活性中心的刚性。最后，我们表明，其他cupredoxins不完全遵循耦合失真模型，以及，提高怀疑，进一步替代模型来描述铜中心的几何形状需要开发，而机架引起的贡献的重要性不应低估。我们提供了一个绿色单核单域铜氧还蛋白的第一个晶体结构。结构分析表明，耦合畸变模型可能无法解释一些铜氧还蛋白的行为。
Cupredoxins are widely occurring copper-binding proteins with a typical Greek-key beta barrel fold. They are generally described as electron carriers that rely on a T1 copper centre coordinated by four ligands provided by the folded polypeptide. The discovery of novel cupredoxins demonstrates the high diversity of this family, with variations in terms of copper-binding ligands, copper centre geometry, redox potential, as well as biological function. AcoP is a periplasmic cupredoxin belonging to the iron respiratory chain of the acidophilic bacterium Acidithiobacillus ferrooxidans. AcoP presents original features, including high resistance to acidic pH and a constrained green-type copper centre of high redox potential. To understand the unique properties of AcoP, we undertook structural and biophysical characterization of wild-type AcoP and of two Cu-ligand mutants (H166A and M171A). The crystallographic structures, including native reduced AcoP at 1.65 Å resolution, unveil a typical cupredoxin fold. The presence of extended loops, never observed in previously characterized cupredoxins, might account for the interaction of AcoP with physiological partners. The Cu-ligand distances, determined by both X-ray diffraction and EXAFS, show that the AcoP metal centre seems to present both T1 and T1.5 features, in turn suggesting that AcoP might not fit well to the coupled distortion model. The crystal structures of two AcoP mutants confirm that the active centre of AcoP is highly constrained. Comparative analysis with other cupredoxins of known structures, suggests that in AcoP the second coordination sphere might be an important determinant of active centre rigidity due to the presence of an extensive hydrogen bond network. Finally, we show that other cupredoxins do not perfectly follow the coupled distortion model as well, raising the suspicion that further alternative models to describe copper centre geometries need to be developed, while the importance of rack-induced contributions should not be underestimated. We provide the first crystallographic structure of a green mononuclear monodomain cupredoxin. Analysis of the structure suggests that the coupled distortion model might not explain the behaviour of some cupredoxins.
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DOI：
10.1107/s090744491003982x
发表时间：
2011-04
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Evans PR
通讯作者：
Evans PR
DOI：
10.1107/s0907444905036693
发表时间：
2006-01-01
影响因子：
2.2
作者：
Evans, P
通讯作者：
Evans, P
DOI：
10.1007/978-1-62703-691-7_18
发表时间：
2014
期刊：
Methods in molecular biology (Clifton, N.J.)
影响因子：
--
作者：
Dyer, Kevin N;Hammel, Michal;Rambo, Robert P;Tsutakawa, Susan E;Rodic, Ivan;Classen, Scott;Tainer, John A;Hura, Greg L
通讯作者：
Hura, Greg L
影响因子：
8.4
作者：
Bím D;Alexandrova AN
通讯作者：
Alexandrova AN
DOI：
10.1039/c0mt00061b
发表时间：
2011-03
期刊：
Metallomics : integrated biometal science
影响因子：
--
作者：
Choi M;Davidson VL
通讯作者：
Davidson VL