Dictyostelium discoideum SECIS elements. (a) SECIS elements in D. discoideum selenoprotein genes. Sequences conserved in eukaryotic SECIS elements are shown in red, and Dictyostelium-specific conserved sequences are shown in blue. (b) Alignment of D. discoideum SECIS elements. A UGUA sequence preceding the SECIS core, and a U-U mismatch in the stem-loop structure represent additional conserved features in Dictyostelium SECIS elements. Black and grey highlighting shows sequence conservation.