They include the N-terminal scaffold attachment factor -A / B , acinus and PIAS ( SAP ) domain , the Proline - Isoleucine - Asparagine -Ile- Threonine ( PINIT ) motif , the RING finger domain - Zinc finger -like zinc -binding domain ( RLD ) , the highly acidic domain ( AD ) , the SUMO-interacting motif ( SIM ) , and the serine / threonine -rich C-terminal region ( S / T ) .