A. Structure of the productive eIF2B•eIF2 complex.2 eIF2B is in approximately the same orientation as in Figure 2. eIF2α and γ are colored gold; the visible portion of eIF2β is orange. The structure is similar to the structure of the eIF2B•eIF2 complex in reference12.The alternative eIF2α- and eIF2γ-binding surfaces observed in the structure of the eIF2B•eIF2 complex from reference13 are circled and labeled. Note that the eIF2B•eIF2 structure in reference13 is similar to the structure of the nonproductive eIF2B•eIF2(α-P) complex2, 13, 16 (panel B).
B. Structure of the nonproductive eIF2B•eIF2(α-P) complex.2 The orientation and coloring are the same as in panel A. The structure is similar to the structures of the eIF2B•eIF2(α-P) complex in references13, 16, and to the structure of the eIF2B•eIF2 complex in reference13.