May mediate protein transfer from the SecYEG translocon to the periplasmic chaperone network via its periplasmic C-terminal region (PubMed:24855643). In addition, at the cytosolic site, acts as a negative regulator of RcsB (PubMed:26092727). In stationary phase, the FtsH-dependent degradation of YfgM ensures the release of RcsB from YfgM and thereby permits cellular protection by the Rcs phosphorelay system (PubMed:26092727). May coordinate stress responses across the inner membrane via a dynamic protein-protein interaction network inside and outside of the membrane (PubMed:26092727). Is stable during exponential growth and degraded in stationary phase by the essential FtsH protease. Degradation is influenced by the alarmone (p)ppGpp, but not by inorganic polyphosphate (polyP), RpoS, RcsB or PpiD. Interacts with the SecYEG translocon (PubMed:24855643, PubMed:31699901). Forms a complex with PpiD (PubMed:21210718, PubMed:24855643, PubMed:31699901). Also interacts with RcsB (PubMed:26092727). The first 14 N-terminal residues form the YfgM degron, which directs the protein to FtsH for proteolysis. Deletion of the gene in combination with either surA or skp causes increased sensitivity to vancomycin and exacerbates the RpoE-dependent envelope stress response in a skp deletion strain (PubMed:24855643). Strains lacking the gene show a decreased survival rate at low pH (PubMed:25403562). Several cell envelope proteins are misfolded/mistargeted and turned-over in the absence of YfgM, including HdeB and AnsB (PubMed:25403562). Belongs to the YfgM family.