ABSTRACT
Iron-responsive elements (IREs) are cis-acting messenger ribonucleic acid (mRNA) stem-loop or hairpin structures that specifically
bind cytoplasmic iron regulatory proteins (IRP1, IRP2) [1-4]. An
IRE-RNA is a ∼30-nucleotide structure formed by two RNA helices that are separated by a bulged cytosine residue, and by a 6-
nucleotide loop of the sequence 5′-CAGUGN -3′ (N is usually a pyrimidine). The sequence of the loop and the bulged nucleotide
are highly conserved [2, 5-9] (Fig. 17.1). The two IRPs, which are
highly conserved themselves, bind IRE-RNA structures in a variety of
animal mRNAs that appeared at various times during evolution [10]
and have been extensively characterized [11-15]. The term “iron
Figure 17.1 Structure of ferritin and mt-aconitase IRE-RNA. Abbreviation: mt-aconitase, mitochondrial aconitase.
