Figure 7.—

Time course of intein splicing in BasGFP. Western blot analysis with anti-GFP antibody of proteins from yeast carrying a BasGFP intein incubated for the indicated periods after stopping transcription induction at 18° or 30°. (A) Time courses of the splicing of intein^WT and intein⁵⁰³. At 30°, intein^WT (top left) spliced rapidly, while intein⁵⁰³ (top right) barely spliced. At 18°, intein⁵⁰³ (bottom right) spliced at a reasonable speed but was slower to splice than intein^WT (bottom left). (B) Time courses of the splicing of intein^WT and intein^Dd. Dead intein did not splice from its host protein. Note that the time courses of the splicing of a BasGFP-intein^WT at 30° done on 2 different days (top left in A and right in B) were very similar, indicating that the splicing reaction is reproducible. (C) Quantification of BasGFP-intein splicing. The y-axis is the ratio of the amount of unspliced BasGFP intein to the total amount of BasGFP and BasGFP intein. The x-axis is the time (in minutes) when yeast cells were harvested. The moment at which transcription induction was stopped was time zero. The calculated, pseudo-first order, splicing halftime is presented following the temperature of splicing and the name of each intein allele.