An RNA polymerase II transcription factor has an associated DNA-dependent ATPase (dATPase) activity strongly stimulated by the TATA region of promoters.

Abstract

A transcription factor required for synthesis of accurately initiated run-off transcripts by RNA polymerase II has been purified and shown to have an associated DNA, dependent ATPase (dATPase) activity that is strongly stimulated by the TATA region of promoters. This transcription factor, designated .delta., was purified more than 3000-fold from extracts of crude rat liver nuclei and has a native molecular mass of approximately 230 kDa. DNA-dependent ATPase (dATPase) and transcription activities copurify when .delta. is analyzed by hydrophobic interaction and ion-exchange HPLC, arguing that transcription factor .delta. possesses an ATPase (dATPase) activity. ATPase (dATPase) is specific for adenine nucleotides; ATP and dATP, but not CTP, UTP, or GTP, are hydrolyzed. ATPase (dATPase) is stimulated by both double-stranded and single-stranded DNAs, including pUC18, ssM13, and poly(dT); however, DNA fragments containing the TATA region of either the adenovirus 2 major late or mouse interleukin 3 promoters stimulate ATPase as much as 10-fold more effectively than DNA fragments containing nonpromoter sequences. These data suggest the intriguing possibility that .delta. plays a critical role in the ATP (dATP)-dependent activation of run-off transcription through a direct interaction with the TATA region of promoters.