Part of the SNAPc complex required for the transcription of both RNA polymerase II and III small-nuclear RNA genes. Binds to the proximal sequence element (PSE), a non-TATA-box basal promoter element common to these 2 types of genes. Recruits TBP and BRF2 to the U6 snRNA TATA box. Part of the SNAPc complex composed of 5 subunits: SNAPC1, SNAPC2, SNAPC3, SNAPC4 and SNAPC5. SNAPC2 interacts with TBP and SNAPC4.