This family contains the cytoplasmic (N-terminal) domain of RseA, the transmembrane anti-sigma-E factor. RseA is degraded during sigma-E-dependent transcription caused by bacterial envelope stress such as heat shock. It is an inner membrane protein with an N-terminal cytoplasmic domain that binds sigma-E and blocks its transcriptional activity, and a C-terminal periplasmic domain that binds RseB, an auxiliary negative regulator. Under inducing conditions, RseA is rapidly degraded and sigma-E is released into the cytoplasm, where it can bind core RNAP and induce its regulon. It has been shown that just the N-terminal domain is sufficient to bind and inhibit sigma-E. The C-terminal domain may interact with other proteins that signal periplasmic stress.