Superoxide dismutases serve to convert damaging superoxide radicals, a key form of ROS, to less damaging hydrogen peroxide that can be converted into water by catalase action. May be involved protection against extracellular stress. 2 H(+) + 2 superoxide = H2O2 + O2 Binds 1 copper ion per subunit. Binds 1 zinc ion per subunit. Covalently-linked GPI-modified cell wall protein (GPI-CWP). Unlike SOD4 and SOD5, SOD6 is not regulated during yeast to hyphae transition or by temperature. Up-regulated during biofilm formation and expression is controlled by HAP43. The GPI-anchor is attached to the protein in the endoplasmic reticulum and serves to target the protein to the cell surface. There, the glucosamine-inositol phospholipid moiety is cleaved off and the GPI-modified mannoprotein is covalently attached via its lipidless GPI glycan remnant to the 1,6-beta-glucan of the outer cell wall layer (By similarity). Belongs to the Cu-Zn superoxide dismutase family.