An anti-sigma factor for extracytoplasmic function (ECF) sigma factor sigma-E (RpoE). ECF sigma factors are held in an inactive form by an anti-sigma factor until released by regulated intramembrane proteolysis (RIP). RIP occurs when an extracytoplasmic signal triggers a concerted proteolytic cascade to transmit information and elicit cellular responses. The membrane-spanning regulatory substrate protein is first cut periplasmically (site-1 protease, S1P, DegS), then within the membrane itself (site-2 protease, S2P, RseP), while cytoplasmic proteases finish degrading the anti-sigma factor, liberating sigma-E (By similarity). Interacts 1:1 with ECF RNA polymerase sigma-E (RpoE); this inhibits the interaction of sigma-E with the RNA polymerase catalytic core and leads to a decreased expression of sigma-E-regulated genes. Interacts with RseB with 1:1 stoichiometry. The liberated N-terminus forms a complex with SspB and RpoE (By similarity). Following cleavage by DegS the large fragment of the protein is still in the inner membrane and retains its anti-sigma-E activity. The N-terminal cytosolic domain interacts with sigma-E. After degradation by RseP binds to SspB, targeting RseA for degradation by the ClpX-ClpP protease (By similarity). The C-terminal periplasmic domain interacts with RseB and is also the target for DegS. Sequentially cleaved by DegS (a site-1 protease) in its periplasmic domain between Val-147 and Ser-148, then by RseP (a site-2 protease). The N-terminal fragment is then degraded by primarily ClpX-ClpP in an ATP-dependent fashion. Sequential cleavage by DegS, RseP and ClpX-ClpP frees RpoE from RseA (By similarity). Belongs to the RseA family.