Actino-pnp RNA motif

The Actino-"pnp" RNA motif is a conserved structure found in actinobacteria that is apparently in the 5' untranslated regions of genes predicted to encode exoribonucleases. The RNA element's function is likely analogous to an RNA structure found upstream of polynucleotide phosphorylase genes in "E. coli" and related enterobacteria. In this latter system, the polynucleotide phosphorlyase gene regulates its own expression levels by a feedback mechanism that involves its activity upon the RNA structure. However, the "E. coli" RNA appears to be structurally unrelated to the Actino-"pnp" motif.