Analysis of the interaction modes of Jatropha curcas ribosome inactivating proteins Curcin and Curcin C with adenosine and adenine

Abstract:

Jatropha curcas ribosome-inactivating proteins Curcin and Curcin C have N-glycosidase activity, but their in vitro translation inhibition ability is significantly different, which implies that there are also differences in the N-glycosidase activity of the two proteins. In order to explore the structural basis for this difference, this study used trRosetta to predict the tertiary structure of the two proteins, and evaluates the quality of the predicted tertiary structure model through PROCHECK and Qmean.The structure of adenine and adenosine was optimized by Chem3D, and the amino acid composition of Curcin and Curcin C active site was predicted by UCSF Chimera.Finally, AutoDock was used for molecular docking to predict the interaction of two protein model with adenine and adenosine. The docking results showed that the interaction modes between the two proteins and adenine were similar, but the key amino acid Arg of Curcin did not participate in the interaction with the ligand. In addition, the binding energy of Curcin C to adenine and adenosine is lower than that of Curcin, and the difference between the binding energy of Curcin C to adenosine and adenine is also higher than that of Curcin.This result implies that the difference in activity between Curcin and Curcin C is related to the structural features at the active site, and the key amino acid Arg in Curcin C is closer to the binding sites of adenine and adenosine.This will lead to lower binding energy between Curcin C and the substrate, which is more conducive to the catalytic reaction.