HELZ is a member of the superfamily I class of RNA helicases. RNA helicases alter the conformation of RNA by unwinding double-stranded regions, thereby altering the biologic activity of the RNA molecule and regulating access to other proteins.

Wagner et al. (1999) found that the protein contains several motifs characteristic of members of the RNA helicase superfamily I, including a putative purine nucleotide-binding site. By Northern blot analysis, Nomura et al. (1994) demonstrated ubiquitous expression of HELZ. Using the gene trapping method, Wagner et al. (1999) identified the mouse homolog of HELZ and found widespread spatial and temporal expression throughout murine embryonic development.