Fig. 3.

Purification of MSA-2 to near homogeneity. (A) Transcriptional assay of the Mono S fractions. In vitro transcription reactions were reconstituted as described in the legend to Fig. 2D. All reactions contained HNF-4 but no Mediator was added. (B) The peak fraction (#17) was rigorously assayed for MSA-2 activity in the presence or absence of PC2 with reactions reconstituted as in A. (C) Silver staining of an SDS/PAGE analysis of fractions eluting from the final Mono S column. Candidate bands that correlated with activity throughout the various chromatography steps are marked with arrowheads.