Structure-based design of a pathway-specific nuclear import inhibitor

Abstract
Kapβ2 (also called transportin) recognizes PY nuclear localization signal (NLS), a new class of NLS with a R/H/Kx(2–5)PY motif. Here we show that Kapβ2 complexes containing hydrophobic and basic PY-NLSs, as classified by the composition of an additional N-terminal motif, converge in structure only at consensus motifs, which explains ligand diversity. On the basis of these data and complementary biochemical analyses, we designed a Kapβ2-specific nuclear import inhibitor, M9M.