FIG 8.
Model for the functional tripartite DctS/DctA/DctB complex for sensing fumarate and succinate in B. subtilis. According to the model, DctB is the primary site for perception of fumarate and succinate, which are then transmitted to PASP of DctS. The putative sites for DctA/DctS interaction and the proposed routes for signal transfer are shown. Transport of fumarate and succinate modifies the interaction between DctA and DctS (dashed and kinked C-terminal helix in DctA), which affects activity or signal transmission to the kinase domain. Abbreviations: PASP, periplasmic PAS (Per-ARNT-Sim) domain; PASC, cytoplasmic PAS (Per-ARNT-Sim) domain; Kin, kinase domain; P, phosphoryl group; Succ, succinate.