FIG. 3.

Identification of the ω site in Ecm331p. Sixty-six, 40, 34, or 28 amino acids (aa) from the C terminus of Ecm331p (A) (potential ω sites are underlined) targeted fluorescent reporters to the cell periphery, but 20 C-terminal amino acids did not (B). (C) That G390 and S392 were the ω and ω + 2 sites, respectively, in Ecm331p was verified by showing that amino acid substitutions permitted by the ω rules (G390D, G390S, and S392D) did not interfere with cell surface targeting, whereas substitutions not permitted by the ω rules (G390T, G390R, and S392Q) caused accumulation of fluorescent reporters in intracellular endoplasmic reticulum-like structures.