Figure 5.

Structure of trinucleotide cap analog [m⁷Gpp_SpApG D2 (S_P), chain A] in complex with eIF4E. The sulfur atom is represented as a yellow sphere, and the missing part of the C-terminal loop (the electron density was not well-defined in the X-ray structure) is marked by a white dashed line. The surface of the protein was colored according to Coulombic potential (panel A) calculated using the UCSF Chimera tool⁵⁵ or color coded by ¹⁵N HSQC chemical shift differences between m⁷GpppApG and m⁷GTP bound eIF4E (panel B).