FIGURE 8.

Summary of SF3a structural and functional domains. Schematic representations of SF3a120 and SF3a66 are as described in Figs. 1A and 2A, respectively. For SF3a60 (accession no. Q12874) the SAP (SAF-A/B, Acinus, and PIAS motif) and the zinc finger domain (Zn) are indicated. Thick lines represent sequences required for intersubunit interactions (Ref. 14 and this study). Black lines indicate sequences essential for interactions; gray lines mark sequences that may contribute to binding. The NLS in SF3a120 and SF3a60 as well as the zinc finger domains of SF3a60 and SF3a66 required for the assembly of the functional 17S U2 snRNP are indicated.