Unique hexameric structure of copper-containing nitrite reductase of an anammox bacterium KSU-1
Unique hexameric structure of copper-containing nitrite reductase of an anammox bacterium KSU-1
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DOI：
10.1016/j.bbrc.2020.03.144
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发表时间：
2020-06-04
影响因子：
3.1
通讯作者：
Fujii, Takao
中科院分区：
文献类型：
--
作者：
Hira, Daisuke;Matsumura, Misa;Fujii, Takao
厌氧氨氧化（anammox）和反硝化是两种不同的微生物反应，形成氮气。厌氧氨氧化反应的初始步骤--亚硝酸盐还原为一氧化氮--被认为是由异化亚硝酸盐还原酶的同系物催化的，已知亚硝酸盐还原酶参与反硝化作用。在这里，我们揭示了含铜亚硝酸盐还原酶（CuNIR）的菌株KSU-1，厌氧氨氧化细菌的晶体结构。CuNIR具有独特的同源六聚体结构，在同源三聚体之间具有三个二硫键，尽管三聚体与已知的CuNIR类似。动力学和诱变分析表明，六聚体结构是重要的电子转移反应。(C)2020爱思唯尔公司All rights reserved.
Anaerobic ammonium oxidation (anammox) and denitrification are two different microbial reactions that form nitrogen gas. The initial step in the anammox reaction-reduction of nitrite to nitric oxide-is thought to be catalyzed by homologs of dissimilatory nitrite reductase, which is known to be involved in denitrification. Here, we reveal the crystal structure of the copper-containing nitrite reductase (CuNIR) of strain KSU-1, an anammox bacterium. CuNIR had a unique homohexameric structure with three disulfide bridges between homotrimers, although the trimer was similar to that of known CuNIRs. Kinetic and mutagenesis analyses suggested that the hexameric structure is important for the electron transfer reaction. (C) 2020 Elsevier Inc. All rights reserved.