ZmSUN4 cDNA and protein features. (A) ZmSUN4 (genotype W23) full-length cDNA, showing the 5' and 3' UTRs, open reading frame (ORF), and poly-A tail. A diagram of the protein indicates domain locations as described in Figure 3. (B) Annotated protein sequence predicted from full-length cDNA ORF (GenBank GU453173). Color scheme is the same as in Figure 3. Amino acid residues below the ZmSUN4 sequence show divergent residues of the duplicated locus on chromosome 3L, ZmSUN3, genotype B73.