Construction of cell-free anammox reaction system

本研究参照厌氧氨氧化反应机理模型，构建了无细胞厌氧反应系统。获得了以下关于系统构建的重要发现。(1)肼合成酶催化NO和NH 4+合成肼，并具有异二聚体血红素蛋白NaxLS。(2)在KSU-1菌株中，铜型亚硝酸盐还原酶（Cu-Nir）合成了一种中间产物NO，尽管细胞色素cd 1 Nir仅在其他厌氧氨氧化细菌中发现。(3)一种多血红素蛋白，羟胺氧化还原酶（HAO），催化NO和羟胺的相互转化。

This study was performed to construct cell-free anaerobic reaction system by reference to the previously described model for mechanism of anammox. The following important findings for construction of the system were obtained. (1) Hydrazine was synthesized from NO and NH4+ catalyzed by hydrazine synthase with a heterodimer heme protein, NaxLS. (2) An intermediate, NO, was synthesized by Cu-type nitrite reductase (Cu-Nir) in strain KSU-1 although cytochrome cd1 Nir has only been known in other anammox bacteria. (3) A multiheme protein, hydroxylamine oxidoreductase (HAO), catalyzed inter-conversion of NO and hydroxylamine.