title: An Oxidoreductase AioE is Responsible for Bacterial Arsenite Oxidation and Resistance.
abstract: Previously, we found that arsenite (AsIII) oxidation could improve the generation of ATP/NADH to support the growth of Agrobacterium tumefaciens GW4. In this study, we found that aioE is induced by AsIIIand located in the arsenic island near the AsIIIoxidase genes aioBA and co-transcripted with the arsenic resistant genes arsR1-arsC1-arsC2-acr3-1. AioE belongs to TrkA family corresponding the electron transport function with the generation of NADH and H+. An aioE in-frame deletion strain showed a null AsIIIoxidation and a reduced AsIIIresistance, while a cytC mutant only reduced AsIIIoxidation efficiency. With AsIII, aioE was directly related to the increase of NADH, while cytC was essential for ATP generation. In addition, cyclic voltammetry analysis showed that the redox potential (ORP) of AioBA and AioE were +0.297 mV vs. NHE and +0.255 mV vs. NHE, respectively. The ORP gradient is AioBA > AioE > CytC (+0.217 ~ +0.251 mV vs. NHE), which infers that electron may transfer from AioBA to CytC via AioE. The results indicate that AioE may act as a novel AsIIIoxidation electron transporter associated with NADH generation. Since AsIIIoxidation contributes AsIIIdetoxification, the essential of AioE for AsIIIresistance is also reasonable.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Yushan
authors.initials: Y
authors.lastname: Han
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Kaixiang
authors.initials: K
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Xia
authors.initials: X
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Mingshun
authors.initials: M
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China.
authors.forename: Gejiao
authors.initials: G
authors.lastname: Wang
mesh_terms: D016960:Agrobacterium tumefaciens / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018053:Arsenites / Q000378:metabolism* / Q000494:pharmacology*; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D023061:Gene Order; D009243:NAD / Q000378:metabolism; D009876:Operon; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018053:Arsenites; D001426:Bacterial Proteins; D009243:NAD; D010088:Oxidoreductases