Rnase p1

Anti-HA antibody 8G5F is a monoclonal antibody produced by immunizing mice with a keyhole limpet hemocyanin-conjugated HA peptide. The anti-V5 antibody was purchased from Serotec Inc. Anti-Lea1, anti-Prp5, anti-Msl5 and anti-Prp8 are polyclonal antibodies produced by immunizing rabbits with full-length recombinant protein (Lea1) or a segment of the corresponding proteins (amino acid residues 510–480 for Prp5, 273–412 for Msl5 and 1–115 for Prp8) expressed in Escherichia coli. Protein A-Sepharose CL-4B was purchased from GE Healthcare, SuperScript III from Invitrogen, proteinase K from MD Bio Inc. and RNase H from Promega. Dinucleotide 4-thio-UpG was purchased from Dharmacon. SP6 RNA polymerase was purchased from Promega, RNase P1 from Sigma, and RNasin and T4 RNA ligase 2 were from Enzymatics.

Anti-V5 antibody was purchased from Serotec Inc. Anti-HA antibody was produced by immunizing mice with a keyhole limpet hemocyanin (KLH)-conjugated HA peptide (unpublished). Anti-Prp16, anti-Prp22, anti-Prp8, anti-Ntc20, anti-Yju2, anti-Cwc2 and anti-Cwc25 polyclonal antibodies were produced by immunizing rabbits with fragments or full-length recombinant Prp16 (1-298), Prp22 (1-484), Prp8 (1-115), Ntc20, Yju2, Cwc2 and Cwc25 proteins, respectively. Dinucleotide 4-thio-UpG was purchased from Dharmacon. SP6 RNA polymerase was purchased from Promega, RNase P1 from Sigma, and RNasin and T4 RNA ligase 2 from Enzymatics. Protein A-Sepharose CL-4B and IgG Sepharose were purchased from GE Healthcare. Complete, EDTA-free Protease Inhibitor Cocktail was purchased from Roche. TEV protease with a mutation (Ser219Asn) at the internal self-cleavage site was a kind gift of Hung-Ta Chen (Institute of Molecular Biology, Academia Sinica).