Structural insight into the catalytic mechanism of arsenate reductase from Synechocystis sp. PCC 6803

• Published in: Environmental Arsenic in a Changing World pp. 95 - 96
• Main Authors: Yan, Y., Ye, J., Zhang, X., Xue, X.M., Zhu, Y.G.
• Format: Book Chapter
• Language: English
• Published: CRC Press 2019
• Edition: 1
• Subjects: Inductively Coupled Plasma Mass Spectrometry; Monomethylarsonic Acid; Arsenate Reductase; Hydride Generation Atomic Fluorescence Spectroscopy; Arsenite Efflux; Size Exclusion Chromatography; Unit Cell Parameters; Dimethylarsinic Acid; Yangtze River; Bacteria Sulfate Reduction; Yangtze; AS3MT; Molecular Replacement Method; Datong Basin; Arsenate Reduction; GSH System; SEM; Hanging Drop Vapor Diffusion Method; Soil Contamination; Ars Operon; Essential Cysteine Residues; NMR Structure
• ISBN: 1138486094; 9781138486096
• DOI: 10.1201/9781351046633-37

Arsenate reductases are the key enzymes in biological arsenic detoxification by catalyzing the intracellular reduction of arsenate to arsenite, and arsenite could be subsequently pumped out of the cells by ArsB or Acr3. The arsenate reductase from cyanobacterium Synechocystis sp. Strain PCC 6803 (SynArsC) shows sequence homology with the thioredoxin-dependent arsenate reductase family, while utilizes the glutathione/glutaredoxin system for arsenate reduction. SynArsC is classified as a novel thioredoxin/glutaredoxin hybrid arsenate reductase family. Here we report the crystal structures of SynArsC in the native and phosphate-bound states at 1.37 and 1.55 Å resolutions, respectively. The structures are mostly similar, but also show differences with implications in SynArsC's arsenate reduction mechanism. Our results provide insights into SynArsC's structure-function relationship and its enzymatic mechanism.