S-layer large protein. May form the highly ordered outer sheath. The mushroom-shaped unit cells of the Sulfolobales' S-layers may consist of three SlaB subunits and six SlaA subunits. Glycosylated. C-terminal glycosylation sites are modified with a heterogeneous family of glycans, with the largest having a composition Glc(1)Man(2)GlcNAc(2) plus 6-sulfoquinovose (QuiS). Belongs to the Sulfolobales SlaA family.