Is the anti-sigma factor for SigW. The presence of RsiW leads to the inactivation of SigW, and its proteolytic destruction to sigma-W activation (By similarity). Binds 1 Zn(2+) ion per subunit. Site-2 clipped RsiW is released from the membrane to the cytoplasm. Is processed by three successive proteolytic events. First, the extracellular region of RsiW is cleaved by PrsW (Site-1 cleavage) in response to cell envelope stresses. Next, it undergoes cleavage at an intramembrane site (Site-2 cleavage) mediated by RasP. This cleavage uncovers a cryptic proteolytic tag with conserved alanine residues in the transmembrane segment, that is recognized mainly by the ClpXP protease, which completely degrades the protein in the cytoplasm and leads to the induction of the sigma-W-controlled genes (By similarity). Belongs to the zinc-associated anti-sigma factor (ZAS) superfamily. Anti-sigma-W factor family.