Identification and characterization of Prp45p and Prp46p, essential pre-mRNA splicing factors

Prp46p coprecipitates with Prp45p in vitro. (A) ³⁵S-methionine-labeled full-length Prp46p or fragments of the regions indicated were produced in vitro. (B) His₆-Prp45p affinity purified from E. coli extract was incubated with the in vitro produced Prp46 polypeptides on ice for 1 h before adding antipentahistine antibodies bound to protein A-Sepharose beads, or beads alone as a control. The pellets and supernates (1.6%) were analyzed by SDS-PAGE and the ³⁵S-labeled Prp45 polypeptides were visualized by autoradiography.