Extended Data Fig. 1. Topology diagram of KsTsrM depicting the different domains.

The blue dot represents the conserved Arg residue that occupies the lower axial position of the Cbl, which is shown as two purple lines. The three yellow spheres on the loop after α₁ of the TIM barrel represent the three conserved cysteines that coordinate the [4Fe-4S] cluster. The orange sphere on the loop following β₂ of the TIM barrel is a conserved Glu residue that coordinates the unique Fe of the cluster.