Containing unusual carbohydrate-protein

V. Structural Analysis of Glycopeptides and Glycoproteins Containing Unusual Carbohydrate-Protein Linkages... 

Other bacterial coats. Archaebacteria not only have unusual plasma membranes that contain phytanyl and diphytanyl groups (Section A,3)608 but also have special surface layers (S-Iayers) that may consist of many copies of a single protein that is anchored in the cell membrane.609 The surface protein of the hypothermic Staphylothermus marius consists of a complex structure formed from a tetramer of 92-kDa rods with an equal number of 85-kDa "arms."610 611 S-layers are often formed not only by archaebacteria but also by eubacteria of several types and with quite varied structures.612 14 While many bacteria carry adhesins on pili, in others these adhesive proteins are also components of surface layers.615 Additional sheaths, capsules, or slime layers, often composed of dextrans (Chapter 4) and other carbohydrates, surround some bacteria. 

Thermoplasma acidophilum, found in hot springs of pH 1 to 4 and at temperatures up to 80°C has no demonstrable cell wall. The cell membrane of this organism is directly exposed to a hot acid environment. The membrane contains 10 per cent carbohydrate, 25 per cent lipid and 60 per cent protein. The bulk of the membrane carbohydrate is found in an unusual LPS, (mahnose)24-glucose glycerol ether, which is thermostable. 

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