Protein composition and electron microscopy structure of affinity-purified human spliceosomal B complexes isolated under physiological conditions.

ABSTRACT: The spliceosomal B complex is the substrate that undergoes catalytic activation leading to catalysis of pre-mRNA splicing. Previous characterization of this complex was performed in the presence of heparin, which dissociates less stably associated components. To obtain a more comprehensive inventory of the B complex proteome, we isolated this complex under low-stringency conditions using two independent methods. MS2 affinity-selected B complexes supported splicing when incubated in nuclear extract depleted of snRNPs. Mass spectrometry identified over 110 proteins in both independently purified B complex preparations, including approximately 50 non-snRNP proteins not previously found in the spliceosomal A complex. Unexpectedly, the heteromeric hPrp19/CDC5 complex and 10 additional hPrp19/CD

SUBMITTER: Deckert J 

PROVIDER: S-EPMC1592722 | biostudies-literature | 2006 Jul

REPOSITORIES: biostudies-literature