Essential component of the Rcs signaling system, which controls transcription of numerous genes. Plays a role in signal transduction from the cell surface to the histidine kinase RcsC. May detect outer membrane defects. The system controls expression of genes involved in colanic acid capsule synthesis, biofilm formation and cell division. Interacts with DsbC. Contains an N-terminal proline-rich region (PRR), which probably plays an important role in the regulation of function of RcsF and activation of the Rcs signaling system. The formation of the non-consecutive disulfides depends on the periplasmic disulfide isomerase DsbC. The disulfide bond between Cys-109 and Cys-124 is particularly important for the assembly of an active RcsF (PubMed:21454485). Belongs to the RcsF family.