Specificity of yeast one-hybrid clones for binding the –35 GC-rich motif. Gal-4 fusion clones representing 3 Krüppel-like factors and a novel zinc-finger (ZF) protein (GenBank accession number AY117438) were transformed into yeast His3 reporter strains driven by 3 copies of wild-type (WT) or mutant (Mu) -35 motif. Strains were plated on Leu^-His^- plates with or without 3-AT.