Schematic representation of the chimeras. (A) All of the constructs were generated based on the invertase-Wbp1p chimera. Open boxes, hatched boxes, and shaded boxes indicate invertase, Wbp1p, and Emp24p sequences, respectively. Characters in circles indicate the key residues and their mutations: K, KK; S, SS; N, TN; F, FF; A, AA; and L, LV. (B) Amino acid sequences of the transmembrane and the cytoplasmic domains of the constructs. Mutations in key residues are indicated by small letters.