Figure 3.

The NAD⁺ binding pocket. (A) A comparison of the NAD⁺-binding site in the eEF2–ExoA_c–βTAD complex and the eEF2–ExoA_c(R551H)–NAD⁺ mutant complex. In the eEF2–ExoA_c–βTAD complex, ExoA_c is shown in dark brown, eEF2 in light brown and βTAD in black. In the eEF2–ExoA_c(R551H)–NAD⁺ complex, ExoA_c is shown in blue, eEF2 in dark green and NAD⁺ in grey. Residues involved in coordinating NAD⁺ are shown as a ball-and-stick representation. (B) Conformation of L1, and the NAD⁺ and βTAD legends in the NAD⁺-binding site as viewed from the diphthamide residue. When compared with (A), the view is rotated −90° around the x axis and 90° around the z axis. Residue and legend colours are as shown in (A). (C) Transparent surface representation of the complex. Open conformation of L1 (blue cartoon with Asp 461 (D 461) in a ball-and-stick representation) in the eEF2–ExoA_c–βTAD complex. The βTAD (black), the diphthamide (white carbons) and the ExoA_c E551H (blue) are shown as a ball-and-stick representation. (D) Closed conformation of L1 in the eEF2–ExoA_c(E551H)–NAD⁺ complex. The colouring is as in (C), except for NAD⁺ (grey ball and stick). ExoA, exotoxin A; eEF2, elongation factor 2; L, loop.