Fig. 7.

Structure and functional domains of yeast eIF1. (Left) The amino acid sequences of the unstructured NTTs of yeast (y) and human (h) eIF1s are aligned and highlighted in green. The substitutions in −M1, −M2, and −M3 mutants of yeast eIF1 are shown below in red, which impair the interaction of eIF1 with the eIF2β NTD and eIF5 CTD in vitro. (Right) Ribbon model of yeast eIF1 indicating the positions of the −M4, −M5, and 93-97 (32) as well as the location of the “KH” and “KR” areas. The effects of the −M5 mutation on the interaction of eIF1 with the eIF3c NTD in vitro or native 40S subunits in vivo and of the −M4 mutation on eIF1 binding to the eIF2β NTD and the eIF5 CTD in vitro (180) are summarized. The interaction of α1 and the β1-β2 loop with the 40S subunit is predicted from structural studies (127, 178). (Reproduced from reference 180 with permission of the publisher.)