Fig. 4.

Effect of 4EGI-1 on the eIF4E/m⁷GTP/4E-BP1 complex. (A) Comparison of a portion of the eIF4E/m⁷GTP/4EGI-1 (PDB ID code 4TPW, Left and Middle) and eIF4E/m⁷GTP/4E-BP1 (Right) structures. (B) HSQC spectrum of unlabeled eIF4E/m⁷GTP bound to ¹⁵N-4E-BP1_44–87, in the absence (red) or presence (cyan) of 4EGI-1. Residues showing minor chemical shift perturbations are boxed and enlarged. (C) HSQC spectrum as described in B, but where unlabeled eIF4E/m⁷GTP is bound to ¹⁵N-4E-BP1_51–64. Residues within the eIF4E ⁵⁴YXXXXLΦ⁶⁰ consensus-binding motif for which the peaks are broadened and disappear almost completely after the addition of 4EGI-1 are boxed and enlarged. (D–F) Fluorescence intensity quenching assay for 4EGI-1 binding to eIF4E, to eIF4E/m⁷GTP/4E-BP1_44–87, or to eIF4E/4E-BP1_51–64.