Figure 4.

The RNA pseudoknots of (A) human antizyme 1 and (B) human antizyme 2. The base pairs absolutely conserved between antizyme 1 and 2 RNA pseudoknots are shown as shaded boxes: burgundy for stem 1 and light blue for stem 2. The stop codon of ORF1 is indicated with a rectangle. The ‘wedged’ nucleotide between stems 1 and 2 of the antizyme 1 pseudoknot is in red. The only three nucleotides of loop 1 conserved between antizymes 1 and 2 are shown in dark blue. Nucleotide substitutions in the pseudoknot region of vertebrate orthologs of antizymes 1 and 4 are shown with green arrows. The substitution pattern is based on the antizyme sequences shown in Figure 3B plus the antizyme from Paralychtys olvaceus. L1, loop 1; L2, loop 2; S1B, stem 1 bottom; S1T, stem 1 top; S2, stem 2.