This region is found in F-box (Pfam:PF00646) and other domain containing plant proteins; it is repeated in two family members. Its precise function is unknown, but it is thought to be associated with nuclear processes [1]. In fact, several family members are annotated as being similar to transcription factors.

1: Systematic identification of novel protein domain families associated with nuclear functions. Doerks T, Copley RR, Schultz J, Ponting CP, Bork P; Genome Res 2002;12:47-56. PMID:11779830