S-layer protein. The S-layer is a paracrystalline mono-layered assembly of proteins which coat the surface of the cell. N-linked glycans consist of the 779 Da trisaccharide beta-ManNAc(Thr)-(1-4)-beta-GlcNAc3NAcA-(1-3)-beta-GlcNAc. Belongs to the Mj S-layer protein family. Was originally thought to be a P-type ATPase.