esc, E(z), Rpd3 and Caf1 copurify in a complex with apparent molecular mass of about 600 kDa.

Source was embryonic nuclear extract of transgenic fly line; bait produced from tagged transgenic construct; prey produced from endogenous gene.

Nuclear extract was fractionated by several chromatographic steps, tracking the distribution of esc- and E(z)-containing fractions by western blot. These fractions were then subjected to anti-FLAG immunoprecipitation and component proteins identified by mass spectroscopy. Identity of copurifying proteins confirmed by western blot.

Source was embryonic nuclear extract of transgenic fly line; bait produced from endogenous gene; prey produced from tagged transgenic construct.

esc and Rpd3 interact in early and late embryos.

Coimmunoprecipitation of tagged prey was determined by pulldown of a radiolabeled LexA DNA probe (that binds specifically to the LexA DNA binding domain).

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

The complex of Su(z)12, E(z), Rpd3, esc and Caf1 has an apparent size of 600-650 kDa (gel filtration).

A histone methyltransferase activity was purified from embryonic nuclear extracts.

Source was embryonic nuclear extract of wild-type fly line; bait produced from endogenous gene; prey produced from endogenous gene.

The 600 kDa PRC2 complex (E(z), esc, Su(z)12, Caf1) is also present in larger 1 MDa complexes that additionally contain Rpd3 and Pcl. The larger 1 MDa PRC2 complex is only observed in 0-16 hr embryos, not in 18-24 hr embryos.

This interaction of esc with Rpd3 is detected only in 0-16 hr embryos, but not in 18-24 hr embryos.

Immunoprecipitation of esc from size fractionated extracts containing complexes of about 1 MDa in size.