Small Nuclear RNA Activating Complex Polypeptide 3 (SNAPC3)

The snRNA-activating protein complex (SNAPc) is required for transcription of both RNA polymerase II and III snRNA genes. Henry et al. (1996) identified the gene for the 50-kD subunit of SNAPc based on partial sequence from the purified protein. The predicted 411-amino acid protein, designated SNAP50, is highly charged (pI = 4.9), and has 2 potential zinc finger domains. Henry et al. (1996) used anti-SNAP50 antibodies in immunoprecipitation and in vitro transcription studies to demonstrate that SNAP50 is part of SNAPc and is required for RNA polymerase II and III snRNA gene transcription. UV crosslinking studies suggest that SNAP50 is in close proximity to the DNA when SNAPc is bound to the proximal sequence element (PSE) of the promoter.