Fig. 1: Structure of the ATfaRel2 antitoxin.
From: Mechanisms of neutralization of toxSAS from toxin–antitoxin modules
a, Cartoon representation of Coprobacillus sp. D7 ATfaRel2 structure. The pZFD core is colored light blue, the C-terminal extension elements are colored salmon and the 51YXXY54 motif is highlighted in dark blue. b, Topology representation of ATfaRel2, colored as in a. c, Superposition of the experimental ATfaRel2 structure (colored as in a) onto the AlphaFold2-predicted structure of the CapRelSJ46 antitoxin domain in the neutralizing state. pZFDCapRel is colored light green and the N-terminal extension that is part of Anchor1 is colored ocher, with the conformational switch region that contains the YXXY neutralization motif colored dark green and labeled in the figure. d, Topology representation of the CapRelSJ46 antitoxin in the neutralizing state, highlighting the circular permutation of ATfaRel2. e, Toxicity neutralization assays probing the 51YXXY54 motif of ATfaRel2 and its scaffolding structure from β1. Serial dilutions of E. coli strains expressing WT FaRel2 alone or coexpressed with ATfaRel2 (WT or V43A, I45A, A50M, Y51A and Y54A variants) were plated on solid LB medium and scored after 16 h at 37 °C. f,g, Binding of WT (f) and Y54A-substituted (g) ATfaRel2 to Y128F-substituted catalytically compromised FaRel2, monitored by ITC.
