FIG. 1.

TFIIA associates with TAF40 in vivo. (A) Two-hybrid assays were used to demonstrate that TFIIA interacts specifically with Toa1 and TAF40. The indicated Gal4 AD fusion proteins were tested for the ability to interact with a DB fusion of Toa2 (DB-Toa2). Approximately 10⁴ cells were spotted onto synthetic complete plates containing either 0 or 40 mM AT. Growth on AT is indicative of an interaction between the two hybrid proteins. The bottom panel shows that strains containing AD-Toa1 or AD-TAF40 do not grow on AT with the DB vector alone. (B) TAF40 stimulates transcription in an artificial recruitment assay. DB-TBP, DB-40, and DB-Fos each stimulate high levels of transcription when tethered to a promoter via a heterologous DB.