TheHfq (Host factor 1) polypeptide is anucleic acidbinding protein involved in the synthesis of many polypeptides. Hfq particularly affects the translation and the stability of several RNAs. In an earlier study, the use of fold recog-nition methods allowed us to detect a relationship between Escherichia coliHfq and the Sm topology. This topology was further validated by a series of biophysical studies and forms ab-sheet ring-shaped hexamer.