The gut symbiont Bacteroides fragilis secretes an antimicrobial ubiquitin homologue (BfUbb) that drives intraspecies bacterial competition. Here, the authors identify a highly conserved TonB-dependent transporter SusCD in B. fragilis as the BfUbb transporter and show species-specific antagonism of BfUbb and the BfUbb bound SusCD complex structure, revealing potential therapeutic applications of BfUbb against enterotoxigenic B. fragilis-related diseases.
- Ming Tong
- Jinghua Xu
- Xiang Gao