trx, nej (CBP) and Sbf copurify as part of TAC1 (trithorax acetylation) complex, estimated to be 1 MDa in size.

Roughly 90% of total nuclear trx and Sbf and roughly 5% of nej are found in the TAC1 complex.

Source was embryonic nuclear extract of wild-type fly line; proteins produced from endogenous genes.

Nuclear extract was fractionated through several different chromatographic steps, selecting for trx-containing fractions. Identity of co-purifying proteins determined by mass spectroscopy and confirmed by western blot.