FIGURE 3.

Structure of ferritin IREs. Selected IREs of nonvertebrate metazoa are shown. All the IREs shown were identified in this work except for those of L. stagnalis (von Darl et al. 1994), C. gigas (Durand et al. 2004), P. leucophryna (Jeong et al. 2006), P. leniusculus (Huang et al. 1999), D. variabilis (Mulenga et al. 2004), and L. vannamei (Hsieh et al. 2006). Structural features of this class of IRE include (1) the UGC bulge where the G is able to pair with the C in the opposite strand; (2) a variability of the UGC consensus sequence; and (3) a G-A pair in some of the structures.