Probably an anti-sigma factor for extracytoplasmic function (ECF) sigma factor sigma-F (SigF), which responds to (hypo)chlorite. ECF sigma factors are held in an inactive form by a cognate anti-sigma factor (Probable). Part of the SigF regulon, induced by chlorite (HClO(2)) under control of SigF. Part of the probable sigF-nrsF operon. Growth not inhibited by chlorite during aerobic growth, slight reduction in lag-phase when grown on minimal medium with lactate and chlorite. Up-regulation of the SigF regulon (Dsui_0156 to Dsui_0159). Belongs to the NrsF anti-sigma-F factor family.