Figure 2.
Human supraspliceosome-associated polypeptides and snRNAs. RNA (A) and protein (B) were extracted from preparative glycerol gradient fractions and electrophoretically resolved through urea-PAGE (A) or SDS-PAGE (B) gels stained with silver (RNA) or coomassie blue (protein). Bar below B represents the fractions of the material pooled for immunopurification with Y12 antibody. (C) Affinity-purified supraspliceosomal proteins run under two SDS-PAGE conditions to resolve either large or small polypeptides. Gels were aligned to show all polypeptides in the affinity-purified fractions and are delineated by the marking between them. The entire gel lanes shown from the two gels in (C) were dissected and each gel slice was subjected to mass spectrometry protein identification. The proteins identified are reported under the Hs PS column in Tables 1–3 and in Supplemental Table S1.