Figure 6.

Purification of a larger NRE-associated protein complex. (A) Comparison of complete HeLa cell nuclear extract (lane 1) with extracts depleted by preincubation with biotinylated NRE–RNA and adsorption on streptavidin beads (lanes 2 and 4) or depleted by preincubation with poly(U) Sepharose in the presence of 2 M KCl (lane 3). Release of NRE-bound proteins from streptavidin beads by RNase treatment (lane 5). ▸, 65-kDa protein; ○, depleted 65-kDa protein; [cirf], enriched proteins; R, RNase A.