Secondary cell wall polymers SCWPs

One of the common surface structures of archea and bacteria are monomolecular crystalline arrays of protein subunits, called S-layers [106-109]. They constitute the outermost component of tlie cell envelope of these procaryotic organisms. S-layer subunits can be aligned in lattices with oblique, square, or hexagonal symmetry. Since S-layers are monomolecular assemblies of identical protein subunits, they exhibit pores of identical size and morphology. A group of nonclassical cell wall polymers, called secondary cell wall polymers (SCWPs), are attached noncova-lently, presumably by a lectin-type interaction, to the S-layer proteins. 

Gram-positive bacteria also have additional anionic polymers (secondary cell-wall polymers, SCWPs), which are covalently attached to the muramic acid residues of the peptidoglyean and attach cell-surface proteins. They can be of the teichoic acid type, linear copolymers of a sugar alcohol and phosphoric acid, or the teichuronic acid type, in which the anionic component is uronic acids.The commonest teichoic acids are based on 1,3-linked glycerol or 1,5-linked ribitol. 

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