Figure 1.

Inhibition of 7SK transcription by anti-hTFIIIB90 antibodies. Transcription reactions in lanes 1–5 were reconstituted with 24 ng rhTFIIIB150 and 40 ng rhTBP. The following protein fractions were added to individual reactions: lanes 1 and 3–5, 1.5 μl cEDF 1 M; lanes 2 and 3, 20 μl cEDF 0.2; lane 4, 20 μl flow-through (FT) from anti-hTFIIIB90 antibodies that had been incubated with a cEDF 0.2 fraction; and lane 5, 20 μl flow-through from nonrelevant antibodies that had been incubated with a cEDF 0.2 fraction. Immuno-depletion is described in Materials and Methods. Transcription reactions were performed as described (13).