Fig. 5.

CD spectra of Rds3p at different temperatures and in vitro splicing assays. (A) Overlay of far UV CD spectra of Rds3p at 20°C (light blue) after heating to 95°C (dark blue) and after recooling the sample to 20°C (pink). The spectra recorded at 20°C almost perfectly overlap, indicating that Rds3p recovers its original structure after this heating cycle. (B) In vitro splicing assay with TAP-SF3b and recombinant Rds3p. GAL1::rds3-1 strain grown under splicing supporting conditions shows that activity is not affected by addition of TAP-purified SF3b complex or recombinant Rds3p. (C) Time course of splicing activity in an extract of GAL1::rds3-1 strain grown in the presence of glucose at 37°C. No splicing activity can be observed in this extract unless it is supplemented with TAP-purified SF3b complex (as a control) or recombinant Rds3p.