Figure 1.

FWD1 is an F-box/WD40-repeat protein related to βTrCP and Slimb. Alignment of the amino acid sequences of FWD1 (Mus musculus), βTrCP (Homo sapiens and Xenopus laevis), Slimb (Drosophila melanogaster), and FWD2 (M. musculus) is shown. Similar amino acids among more than three members are boxed. The seven copies of the WD40 repeats in all four proteins are underlined; the single F-box in each protein is double-underlined. The overall identity to FWD1 is 99% (for human βTrCP), 86% (for Xenopus βTrCP), 70% (for Drosophila Slimb), and 13% (for Mus FWD2).