FIG. 9.

Model of Hfq's role in DsrA-mediated regulation. When initially synthesized, DsrA folds into active and inactive forms. Hfq binds to DsrA molecules, unfolds them, and allows them to refold into active forms and inactive forms. Active DsrA forms regulatory complexes with its targets and leaves the cycle. Alternatively, Hfq and DsrA could form an RNA-protein complex that is active for the regulation of rpoS and hns (lower box). These models are not mutually exclusive.