Fig. 6.
DNA binding by F1 + F2 promotes interaction with Ubc9. (A) GSTUbc9 does not bind to a 15 bp duplex DNA immobilised on streptavidin agarose via a biotin linkage. Unlabelled DNA is used as a negative control. (B) Under the same conditions, PARP-1 F1 + F2 binds to the 15 bp duplex. (C) PARP-1 F1 + F2 is not significantly retained by SUMO-2 agarose in the presence or absence of DNA. Underivatised agarose is used as a negative control. (D) GSTUbc9 binds to SUMO-2 agarose in the absence of DNA. (E) PARP-1 F1 + F2 binds to GSTUbc9 immobilised on glutathione Sepharose in the presence, but not in the absence of DNA. GST is used as a negative control. (F) SUMO-1 binds to immobilised GSTUbc9 in the absence of DNA.