Fig. 4. Functional domains of the sterol glucosyltransferase Ugt51. (A) Schematic drawing of the annotated domains within Ugt51. The amino acid numbers at the borders of each domain are indicated. (B) Various Ugt51 variants were expressed in ugt51Δ cells under the control of either its original promoter (indicated by the prefix Po) or the strong AOX1 promoter (without indication). Resulting strains are grouped and a short-hand designation is given on the left. Their corresponding expression products are depicted schematically in the middle. Persistence of Aox is shown on the right panel. The strains that harbour the GRAM or catalytic domain-mutated Ugt51 retain Aox activity (strains GFP–UGT51-GRAMΔ, GFP–UGT51-Y642P and GFP–UGT51-CATΔ). The PH-domain deletion displayed impaired pexophagy when the enzyme was expressed under its original promoter (strain PoUGT51-PHΔ), but not when it was expressed under the AOX1 promoter (strain GFP–UGT51-PHΔ). The overview of the results for each strain is also shown in the right-hand columns. NT, not tested.