Crystal structures of multicopper oxidase CueO G304K mutant: structural basis of the increased laccase activity

文献类型： 外文期刊

第一作者： Wang, Hanqian

作者： Wang, Hanqian;Yan, Yuhua;Dong, Yuhui;Gong, Yong;Liu, Xiaoqing;Zhao, Jintong;Yue, Qingxia;Fan, Yunliu;Tian, Jian;Wu, Ningfeng;Yan, Yuhua;Gao, Zengqiang;Dong, Yuhui;Zhang, Zhiyong

作者机构：

期刊名称：SCIENTIFIC REPORTS （ 影响因子：4.379； 五年影响因子：5.133 ）

ISSN： 2045-2322

年卷期： 2018 年 8 卷

页码：

收录情况： SCI

摘要： The multicopper oxidase CueO is involved in copper homeostasis and copper (Cu) tolerance in Escherichia coli. The laccase activity of CueO G304K mutant is higher than wild-type CueO. To explain this increase in activity, we solved the crystal structure of G304K mutant at 1.49 angstrom. Compared with wild-type CueO, the G304K mutant showed dramatic conformational changes in methionine-rich helix and the relative regulatory loop (R-loop). We further solved the structure of Cu-soaked enzyme, and found that the addition of Cu ions induced further conformational changes in the R-loop and methionine-rich helix as a result of the new Cu-binding sites on the enzyme's surface. We propose a mechanism for the enhanced laccase activity of the G304K mutant, where movements of the R-loop combined with the changes of the methionine-rich region uncover the T1 Cu site allowing greater access of the substrate. Two of the G304K double mutants showed the enhanced or decreased laccase activity, providing further evidence for the interaction between the R-loop and the methionine-rich region. The cuprous oxidase activity of these mutants was about 20% that of wild-type CueO. These structural features of the G304K mutant provide clues for designing specific substrate-binding mutants in the biotechnological applications.

分类号：

  • 相关文献
作者其他论文 更多>>

微信小程序