Interaction of Sso2509 with aIF2-γ. Lane 1–4, 2.5 pmol of either purified aIF2 subunit and Sso2509 (1/40 of input) were loaded on a 12% polyacrylamide gel followed by western blot analysis with anti-His antibodies. Lane 5, Immunoprecipitation of Sso2509 with anti-2509 antibodies and detection by western blot analysis with anti-His antibodies. Lanes 6, 8, 10 and 12, Co-IP experiments using anti-2509–specific antibodies. Sso 2509 was incubated together with aIF2-α (lane 6), aIF2ß (lane 8), aIF2-γ (lane 10) and trimeric aIF2 (lane 12), respectively. The eluates were separated on a 12% SDS polyacrylamide gel and the proteins were detected by western blot analysis using anti-His antibodies. Lanes 7, 9, 11, 13, mock experiments in the absence of protein Sso2509. The positions of the aIF2-γ, aIF2-α and 2509-specific bands are indicated by arrows.