DnaX ribosomal frameshifting element
The DnaX ribosomal frameshifting element is a RNA element found in the mRNA of the dnaX gene in E. coli. The dnaX gene has two encoded products, tau and gamma, which are produced in a 1:1 ratio.
Source: Wikipedia — DnaX ribosomal frameshifting element (CC BY-SA 4.0)