Non-conserved residues between Impα proteins near to the minor NLS binding region.

(a)Partial alignment of amino acid sequences of Impα proteins from different organisms. Conserved residues are shown in black. The residues S402, K497 and E493 for NcImpα and their equivalent residues for Impα proteins are shown in red. (b) Superposition between Cα of NcImpα and MmImpα structures (performed as described in Fig 5) highlights the residues S402, K497 and E493 of NcImpα (magenta) and the residues T402, S483 and A487 of MmImpα (green). These particular residues may be associated to NLS binding specificity to the minor NLS binding site. E493 side-chain is shown in a hypothetical conformation in this figure because this residue presents lack of electron density in this structure due to its high flexibility.