FIG 3.

Functional analysis of the sequences involved in β-sheet formation. (A) Substitutions in 7 tagged eIF4G(580-1133) fragments. Triplets of aromatic/hydrophobic/charged amino acids (red letters) involved in putative β-sheet structures were replaced with glycines (green letters). Amino acid numbers in green represent the first glycine substitution in each mutated fragment. (B) HEK293 cells were transfected for expression of the indicated fragments (16 h) and synchronized by Th block (24 h). Cell lysates were subjected to immunoblotting or anti-Flag IP/immunoblotting with the indicated antibodies. (C) Binding of eIF3a and eIF4E with eIF4G fragments was quantified and averaged between 3 tests. Error bars represent SEM; asterisks represent Student t test results (P < 0.05).