N-glycosidase mechanism of Trichosanthin.
The interactions between TCS and AMP, ADO, TUB., CMP were studied by crystallographic method, which confirmed that TCS specially recognizes ADE, but does not recognize cytosine. When TCS interacts with mononucletide, the ligand with or without phosphate is not important. The proton H(+) of guanidinum group of Arg163 is shared by N(3) of ADE, but is not received by N(7). This enriches the model of N-glycosidase mechanism about TCS and AMP. This model should suit to the interaction between RIPs and AMP, and reflect the main interaction between RIPs and rRNA. However, the interaction between RIPs and rRNA is more complicated. To comprehensively understand recognition and catalysis of RIPs against rRNA, at least the RIP/RNA segment complex crystal structure should be determined. This RNA segment should contain stem and loop with GAGA sequence.
Wu
S
S
Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.
Lu
X
X
Zhu
Y
Y
Yang
J
J
Dong
Y
Y