Crystal structure of decameric peroxiredoxin (AhpC) from Amphibacillus xylanus
Crystal structure of decameric peroxiredoxin (AhpC) from Amphibacillus xylanus
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DOI：
10.1002/prot.20412
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发表时间：
2005-05-15
影响因子：
2.9
通讯作者：
Miki, K
中科院分区：
文献类型：
--
作者：
Kitano, K;Kita, A;Miki, K
过氧化物酶（Peroxiredoxins，Prxs），也称为AhpC，是一种普遍存在的抗氧化酶家族。细菌AhpC被认为是内源性产生的过氧化氢的主要清除剂。从木双芽孢杆菌中纯化的AhpC与黄素蛋白NADH氧化酶协同作用，对氢过氧化物和烷基氢过氧化物都显示出极高的清除活性。本文报道了A. xylanus AhpC的氧化形式。该酶形成环状（α2）5-十聚体，其结构与先前报道的Prxs相似，特别是与鼠伤寒沙门氏菌的Prxs相似。十聚体的二聚体-二聚体界面表现出适度和保守的疏水相互作用，已提出在生理离子强度下解离。在晶体中，观察到的十聚体之间的小分子的电子密度，并显示出通过桥接的十聚体通过氢键在结晶中发挥独特的作用。
Peroxiredoxins (Prxs), also referred to as AhpCs, are a ubiquitous family of antioxidant enzymes. Bacterial AhpC is recognized as the primary scavenger of endogenously generated hydrogen peroxides. AhpC purified from Amphibacillus xylanus shows extremely high scavenging activity for both hydroperoxide and alkyl hydroperoxide in cooperation with the flavoprotein, NADH oxidase. Here we report the crystal structure of A. xylanus AhpC in its oxidized form. The enzyme forms a ring-like (α2) 5-decamer, the structure of which is similar to those of the previously reported Prxs, and especially to that from Salmonella typhimurium. The dimer-dimer interface of the decamer exhibits moderate and conserved hydrophobic interactions, which have been proposed to dissociate at the physiological ionic strengths. In the crystal, electron densities of small molecules were observed between the decamers and were shown to play a unique role in the crystallization by bridging the decamers via the hydrogen bonds.