2011.07.21,Professor Zhou Congzhao Published a paper entitled “Structure-Guided Activity Restoration of the Silkworm Glutathione Transferase Omega GSTO3-3”in Journal of Molecular Biology

  • Author:#Chen Baoyu、Ma Xiaoxiao#、Guo Pengchao、Tan Xiang、Li Weifang、Yang Jiepin、Zhang Nannan、Chen Yuxing、Xia Qingyou、Zhou Congzhao.
    Abstract

    Glutathione transferases (GSTs) are ubiquitous detoxification enzymes that conjugate hydrophobic xenobiotics with reduced glutathione. The silkworm Bombyx mori encodes four isoforms of GST Omega (GSTO), featured with a catalytic cysteine, except that bmGSTO3-3 has an asparagine substitution of this catalytic residue. Here, we determined the 2.20-Å crystal structure of bmGSTO3-3, which shares a typical GST overall structure. However, the extended C-terminal segment that exists in all the four bmGSTOs occupies the G-site of bmGSTO3-3 and makes it unworkable, as shown by the activity assays. Upon mutation of Asn29 to Cys and truncation of the C-terminal segment, the in vitro GST activity ofbmGSTO3-3 could be restored. These findings provided structural insights into the activity regulation of GSTOs.

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