Prokaryotic cells cytoplasmic domain

Cell envelopes of archaea diifer distinctly from those of bacteria and show remarkable structural and chemical diversity. Murein, the typical sacculus-forming polymer of bacteria, and lipopolysaccharide-containing outer membranes, characteristic of gramnegative bacteria, are not found in archaea. Crystalline surface layers (S-layers) are common in both prokaryotic domains and they consist of protein or glycoprotein subunits (Table 1). However, S-layers in archaea have a form-stabilizing function especially when they are the only envelope layer outside the cytoplasmic membrane, while in bacteria S-layers have no distinct form-stabilizing function. 

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