The superimposition of S. aureus KtrA RCK_C domain with other RCK_C domains.
S. aureus KtrA RCK_C domain, B. subtilis KtrA RCK_C domain (PDB code 4J91), and MthK RCK_C domain (PDB code 3XKD) are shown in lavender, green, and yellow, respectively. The N termini of S. aureus KtrA RCK_C domain and MthK RCK_C domain adopt an α-helix structure, whereas the N terminus of B. subtilis KtrA RCK_C domain has a β-sheet structure.