Importin-β, unlike importin-α, has no direct homologues in yeast, but was purified as a 90-95kDa protein and found to form a heterodimer with importin-α in a number of different cases.
A importina-β, a diferenza da importina-α, non ten homólogos directos nos lévedos, pero purificouse neles unha proteína de 90-95kDa que formaba unh heterodímero coa importina-α en varios experimentos.