Fig 2. The TcA receptor binding domain of TcdA1^W14 is required for N-glycan-mediated intoxication.

(A-B) Representative bright field micrographs of indicated HeLa-Cas9 cells treated with indicated doses of PTC3^TT01 or PTC3^W14 (A). Cell viability was measured using CCK-8 assays and shown in (B). (C-D) MAN1A2-KO, MGAT1-KO, MGAT2-KO, C1GalT1-KO, and HeLa-Cas9-sgCon cells were exposed to 20 nM PTC3^TT01. Representative bright field micrographs (C) and the effects on cell viability (D) were shown. (E) Schematic drawing of indicated TcAs. The N-terminal VRP1 domain (PF03538), the middle Neuraminidase domain (PF18413) and the C-terminal TcA_TcB_BD domains (PF18276) were shown. The RBD-D domains derived from TcdA1^TT01 and TcdA1^W14 are depicted in orange and green, respectively. (F-G) MAN1A2-KO, MGAT1-KO, MGAT2-KO, and HeLa-Cas9-sgCon cells were exposed to 20 nM of the indicated toxins. Representative bright field micrographs were shown (F). Cell viability was measured using CCK-8 assays (G). All error bars indicate mean ± SD. Each of the experiments was repeated three times.