Identification and Characterization of a Redox Sensor Phosphodiesterase from Ferrovum sp. PN-J185 Containing Bacterial Hemerythrin and HD-GYP Domains
Identification and Characterization of a Redox Sensor Phosphodiesterase from Ferrovum sp. PN-J185 Containing Bacterial Hemerythrin and HD-GYP Domains
复制标题
DOI：
10.1021/acs.biochem.0c00021
复制
发表时间：
2020-03-03
期刊：
影响因子：
2.9
通讯作者：
Unno, Masaki
中科院分区：
文献类型：
--
作者：
Kitanishi, Kenichi;Igarashi, Jotaro;Unno, Masaki
第二信使双（3 '，5'）-环二聚鸟苷一磷酸（c-di-GMP）调节细菌中许多重要的生理功能。在这项研究中，我们确定并表征了第一个二聚体，全长，非血红素铁结合磷酸二酯酶（PDE）含有细菌hemerythrin和HD-GYP结构域（Bhr-HD-GYP）。我们发现来自Ferrovum sp. PN-J185的FV18S_09380基因编码的氨基酸序列含有N-末端细菌血红蛋白结构域和C-末端HD-GYP结构域，这是具有针对c-di-GMP的PDE活性的蛋白质的特征。电感耦合等离子体发射光谱分析表明，Bhr-HD-GYP含有4个当量的铁原子，每个亚基，这表明hemerythrin和HD-GYP结构域具有非血红素二铁网站。一个氧化还原依赖的光谱变化预期氧桥非血红素铁与羧酸配体进行了观察，这种氧化还原相互转换是可逆的。然而，不像海洋无脊椎动物的血红蛋白，这是一个氧结合蛋白的功能，BHR-HD-GYP没有形成一个氧加合物，因为快速自氧化。蛋白质的还原亚铁络合物催化c-di-GMP水解成其线性化产物5 '-磷酸鸟苷酰-（3'，5 '）-鸟苷（pGpG），而氧化三价铁络合物没有显著活性。这些结果表明，Bhr-HD-GYP是一种氧化还原和氧传感器酶，其响应于细胞氧化还原状态或氧浓度的变化来调节c-di-GMP水平。我们的研究可能会导致铁氧化细菌Ferrovum sp. PN-J185的生理学的更好的理解。
The second messenger bis(3',5')-cyclic dimeric guanosine mono-phosphate (c-di-GMP) regulates numerous important physiological functions in bacteria. In this study, we identified and characterized the first dimeric, full-length, non-heme iron-bound phosphodiesterase (PDE) containing bacterial hemerythrin and HD-GYP domains (Bhr-HD-GYP). We found that the amino acid sequence encoded by the FV18S_09380 gene from Ferrovum sp. PN-J185 contains an N-terminal bacterial hemerythrin domain and a C-terminal HD-GYP domain, which is characteristic of proteins with PDE activity toward c-di-GMP. Inductively coupled plasma optical emission spectroscopy analyses showed that Bhr-HD-GYP contains 4 equiv of iron atoms per subunit, suggesting both hemerythrin and HD-GYP domains have non-heme di-iron sites. A redox-dependent spectral change expected for oxo-bridged non-heme iron with carboxylate ligands was observed, and this redox interconversion was reversible. However, unlike marine invertebrate hemerythrin, which functions as an oxygen-binding protein, Bhr-HD-GYP did not form an oxygen adduct because of rapid autoxidation. The reduced ferrous iron complex of the protein catalyzed the hydrolysis of c-di-GMP to its linearized product, 5'-phosphoguanylyl-(3',5')-guanosine (pGpG), whereas the oxidized ferric iron complex had no significant activity. These results suggest that Bhr-HD-GYP is a redox and oxygen sensor enzyme that regulates c-di-GMP levels in response to changes in cellular redox status or oxygen concentration. Our study may lead to an improved understanding of the physiology of iron-oxidizing bacterium Ferrovum sp. PN-J185.