Figure 8.

TFIIIA-Mediated Increase in in Vitro Transcription by Pol II.

(A) Immunoprecipitation of the FLAG-tagged second largest subunit of Pol II from a partially purified Pol II holoenzyme.

(B) Ability of partially purified Pol II holoenzyme to transcribe circular (+)-PSTVd in the presence of BSA, TFIIIA-7ZF, or -9ZF. The position of the linear unit-length PSTVd and the concatemers are indicated by and an arrow and a bar, respectively. The transcription products were detected by using a ³²P-labeled strand-specific probe. The specificity of the probe is shown by the detection of T3 phage polymerase generated (+)-PSTVd (40 ng) and (−)-PSTVd (10 ng) in vitro transcripts.