Fig. 5. Impaired activities of eIF2B complex lacking the C-terminal 61 residues of the epsilon subunit. (A) Nucleotide exchange assay with indicated amounts of wild-type eIF2B (squares) eIF2Bε1–651 (triangles, circles) or buffer control (diamonds).Trendlines are exponential curve fits to the data, broken line is for buffer control. (B) Interaction of eIF2 (5 nM) with five-subunit complexes of wild-type eIF2B (lane 2), eIF2Bε1–651 (lane 3) or an equivalent amount of FLAG peptide (100 nM, lane 1) on anti-FLAG M2 resin. eIF2 and eIF2B subunits indicated on the left were probed with the specific antiserum indicated on the right, where 8.5% (eIF2B panels) and 31% (eIF2 panels) of total bound material was loaded in each lane.