FIG. 8.

Spliceosome formation activity of 3′ splice site constructs. Equal amounts of the in vitro-transcribed RNA used in Fig. 6 were incubated under U12-dependent splicing conditions for the times indicated, treated with heparin, and separated on nondenaturing gels. The splicing-specific complexes A and B are well resolved from the nonspecific complex H. Lane 1 shows complexes formed on a U2-dependent adenovirus major late intron precursor incubated in the absence of the anti-U2 snRNA oligonucleotide.