Ye Jun, Nadar S Venkadesh, Li Jiaojiao, Rosen Barry P
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, People's Republic of China.
Department of Cellular Biology and Pharmacology, Florida International University, Herbert Wertheim College of Medicine, Miami, FL 33199, USA.
Acta Crystallogr D Biol Crystallogr. 2014 Jul;70(Pt 7):1907-13. doi: 10.1107/S1399004714009250. Epub 2014 Jun 29.
The structure of glutaredoxin 2 (Grx2) from Escherichia coli co-crystallized with glutathione (GSH) was solved at 1.60 Å resolution. The structure of a mutant with the active-site residues Cys9 and Cys12 changed to serine crystallized in the absence of glutathione was solved to 2.4 Å resolution. Grx2 has an N-terminal domain characteristic of glutaredoxins, and the overall structure is congruent with the structure of glutathione S-transferases (GSTs). Purified Grx2 exhibited GST activity. Grx2, which is the physiological electron donor for arsenate reduction by E. coli ArsC, was docked with ArsC. The docked structure could be fitted with GSH bridging the active sites of the two proteins. It is proposed that Grx2 is a novel Grx/GST hybrid that functions in two steps of the ArsC catalytic cycle: as a GST it catalyzes glutathionylation of the ArsC-As(V) intermediate and as a glutaredoxin it catalyzes deglutathionylation of the ArsC-As(III)-SG intermediate.
大肠杆菌谷氧还蛋白2（Grx2）与谷胱甘肽（GSH）共结晶的结构在1.60 Å分辨率下得到解析。活性位点残基Cys9和Cys12突变为丝氨酸的突变体在无谷胱甘肽情况下结晶的结构在2.4 Å分辨率下得到解析。Grx2具有谷氧还蛋白的N端结构域，其整体结构与谷胱甘肽S-转移酶（GST）的结构一致。纯化的Grx2表现出GST活性。Grx2是大肠杆菌ArsC还原砷酸盐的生理电子供体，它与ArsC进行对接。对接结构可以通过GSH连接两种蛋白质的活性位点来拟合。有人提出Grx2是一种新型的Grx/GST杂交体，在ArsC催化循环的两个步骤中发挥作用：作为GST，它催化ArsC-As（V）中间体的谷胱甘肽化；作为谷氧还蛋白，它催化ArsC-As（III）-SG中间体的去谷胱甘肽化。
