FIG 1 .

Domain architecture of sensor kinases in the BvgS family. (Left panel) Schematic representation of the BvgS dimer comprising VFT, PAS, and histidine kinase (HK) domains, connected to one another with α-helical linkers 1 and 2. The receiver and HPt domains are omitted for clarity. (Right panel) Approximately 30% of BvgS homologues are devoid of the PAS domain and present an α-helical X linker between the VFT and HK domains. Linkers 1 and 2 are rather highly conserved in size (see Fig. 1 in reference 16 and Fig. 3 in reference 19), while the length of linker X is variable (see Fig. 3 in reference 19). Their sequence conservation is shown in Fig. 9.