FIG. 6.
The transcription activities of different stmSNAPcs does not correlate with their abilities to recruit TBP. A whole-cell extract was either left untreated (lanes 1 and 2) or treated with preimmune (PRE-IMM.) antibody beads (lanes 3 and 4) or with a mixture of anti-SNAP190 (α-SNAP190) and anti-SNAP43 (α-SNAP43) antibody beads (lanes 5 to 20). The extracts were then complemented with the proteins indicated above the lanes. The presence (+) or absence (−) of TBP and the amount of the stmSNAPc protein (indicated by the height of the triangle) are indicated over the lanes. The extracts were programmed with the plasmid pU6/Hae/RA.2, which carries the human U6 promoter. The titrations of the stmSNAPcs and the (1-90)RcRd protein were over a threefold range. The transcripts were analyzed by RNase T1 protection. The signals corresponding to correctly initiated U6 RNA (U6) or to a control RNA (IC) included in the reaction mixtures to monitor RNA handling and recovery are indicated to the left of the gel.