Structural Basis of Biological N2O Generation by Bacterial Nitric Oxide Reductase
Structural Basis of Biological N2O Generation by Bacterial Nitric Oxide Reductase
复制标题
DOI：
10.1126/science.1195591
复制
发表时间：
2010-12-17
期刊：
影响因子：
56.9
通讯作者：
Shiro, Yoshitsugu
中科院分区：
文献类型：
--
作者：
Hino, Tomoya;Matsumoto, Yushi;Shiro, Yoshitsugu
一氧化氮还原酶（NOR）是一种含铁酶，它催化一氧化氮（NO）的还原，生成一种主要的温室气体，一氧化二氮（N2O）。在这里，我们报道了铜绿假单胞菌在2.7埃分辨率下的NOR晶体结构。结构揭示了催化双核中心的细节。非血红素铁（Fe-B）由3个His配体和1个Glu配体配位，但缺乏细胞色素氧化酶（COX）中常见的His- tyr共价键。这种结构特性对NOR反应至关重要。虽然NOR的整体结构与COX密切相关，但没有观察到连接COX活性中心和细胞内空间的d -和k -质子通路。NOR反应所需的质子可能来自细胞外侧。
Nitric oxide reductase (NOR) is an iron-containing enzyme that catalyzes the reduction of nitric oxide (NO) to generate a major greenhouse gas, nitrous oxide (N2O). Here, we report the crystal structure of NOR from Pseudomonas aeruginosa at 2.7 angstrom resolution. The structure reveals details of the catalytic binuclear center. The non-heme iron (Fe-B) is coordinated by three His and one Glu ligands, but a His-Tyr covalent linkage common in cytochrome oxidases (COX) is absent. This structural characteristic is crucial for NOR reaction. Although the overall structure of NOR is closely related to COX, neither the D-nor K-proton pathway, which connect the COX active center to the intracellular space, was observed. Protons required for the NOR reaction are probably provided from the extracellular side.