Molecular characterization of the YAO. (A) Diagram of the Ds insertion in YAO. The grey boxes indicate the exons of YAO, the white boxes indicate the UTR regions and the lines indicate the intron regions. The nucleotide numbers are consistent with those in the Arabidopsis genome on TAIR web site. (B) Diagram of predicated domain structure of YAO protein. NLS, nuclear localization signal. (C) Phylogenetic tree of YAO with its homologs from other organisms: EMB2271 from A. thaliana; Os03G0625900 from O. sativa; HsU3-55K from H. sapiens; MmNP_663595.1 from M. musculus; XlAAI57488.1 from X. laevis; CeNP_872030.2 from C. elegans; SpNP_594143.1 from S. pombe; ScRrp9, from S. cerevisiae. (D) Protein alignment of YAO and EMB2271. The seven predicted WD40-repeat domains are underlined.