Figure 1 - Structure of the minimal Tfb2–Tfb5 complex.

(a) Ribbon representation of the Tfb2C–Tfb5 heterodimer (center), where Tfb2C is shown in brown and Tfb5 in blue. Details of intra- and intermolecular interactions are depicted in inserted panels I (for Tfb2C), II and III (for Tfb2C–Tfb5). (b) Representation of Tfb2C and Tfb5 monomers in the same orientation, highlighting the similar fold. The N helix from Tfb2 is not shown. (c) Schematic diagram of Tfb2C–Tfb5 interactions: dashed gray lines represent hydrogen bonds, black broken lines ion pairs and black solid lines van der Waals and hydrophobic contacts.