Mating growth selection to test the screening of affinity-enhanced proteins.

<p>The signal-promoted cells were isolated as methionine- and lysine-prototrophic diploids. Growth of the engineered strains expressing cytosolic Z_WT (A), Z_K35A (B) and Z_I31A (C) as the parental ‘Y₂’ proteins. Five Z variants (ZZ, Z_WT, Z_K35A, Z_I31A and Z₉₅₅) were expressed as the membrane-anchored ‘Y₁’ candidate proteins in each strain. Control indicates the yeast strains without the expression of ‘Y₁’ (transformed with pGK413 mock vector). BY4742 was used as the mating partner.