FIG. 6.

Properties of Efg1 variants in DNA binding and protein interactions. (A) Activation of an MCB-containing promoter by Efg1p deletion variants. S. cerevisiae strain BY600 containing reporter plasmid pMCB (3×MCB-CYC1p-lacZ) was transformed with plasmid pDB16 [ADH1p-GAL4(AD)-EFG1] and corresponding deletion variants, and β-galactosidase activities of selected transformants (Miller units) were determined. Values were derived from four independent transformants in duplicate measurements (± standard deviation). pGAD, negative control vector [ADH1p-GAL4(AD)]; pAP-swap, exchange of Efg1p APSES domain with Efh1 APSES domain. (B) Binding of Efg1p to Czf1p. Transformants of S. cerevisiae Ol1 encoding a LexA-Czf1 fusion protein (pBOM1a) and Efg1 fusions to the Gal4 activation domain (pDB16 or its deletion derivatives) were tested for activation of the lacZ reporter construct (present on pSH18-34). β-Galactosidase activity was determined as with panel A. (C) Binding of Efg1p to Flo8p. Transformants of strain PJ69-4A encoding a fusion of the Gal4 DNA binding domain to a shortened Flo8 protein (BD-Flo8p-ΔC, encoded by pVL4) and Efg1 fusions to the Gal4 activation domain (pDB16 or its deletion derivatives) were tested for activation of the ADE2 and HIS3 reporter genes by growth on supplemented SD medium lacking adenine and histidine.