Fig. 6

Structural similarity analysis of ADP-ribosylation fold-containing proteins. (A) Dendrogram and similarity matrix of 17 clustering members. (B) Homology of Cluster 2 to diphtheria toxin. (C) Homology of Cluster 4 to heat-labile enterotoxin. *P < 0.05, **P < 0.01, and ***P < 0.001.