This family includes ProQ, which is required for full activation of the osmoprotectant transporter, ProP, in Escherichia coli. This family includes several bacterial fertility inhibition (FINO) proteins. The conjugative transfer of F-like plasmids is repressed by FinO, an RNA binding protein. FinO interacts with the F-plasmid encoded traJ mRNA and its antisense RNA, FinP, stabilizing FinP against endonucleolytic degradation and facilitating sense-antisense RNA recognition. ProQ operates as an RNA-chaperone, binding RNA and bringing about both RNA strand-exchange and RNA duplexing. This suggests that in fact it does not regulate ProP transcription but rather regulates ProP translation through activity as an RNA-binding protein.