FIG. 3.

Direct binding of Imp β by the Rev NLS. The indicated purified wild-type (Rev, TNLS) or mutant (Rev M6, Rev M40D, R₅QR₄) GST fusion proteins were coupled to agarose beads and used to construct micro-affinity columns that were then loaded with ∼2 μg of recombinant Imp β or Imp α. Proteins present in the column flow-through (FT) fraction were collected, and bound (B) proteins were eluted from the column by using 800 mM MgCl₂. The FT and B fractions were then subjected to analysis by SDS-PAGE.