Mechanism of osmoprotection by archaeal S-layers: a theoretical study.
Many Archaea possess protein surface layers (S-layers) as the sole cell wall component. S-layers must therefore integrate the basic functions of mechanical and osmotic cell stabilisation. While the necessity is intuitively clear, the mechanism of structural osmoprotection by S-layers has not been elucidated yet. The theoretical analysis of a model S-layer-membrane assembly, derived from the typical cell envelope of Crenarchaeota, explains how S-layers impart lipid membranes with increased resistance to internal osmotic pressure and offers a quantitative assessment of S-layer stability. These considerations reveal the functional significance of S-layer symmetry and unit cell size and shed light on the rationale of S-layer architectures.
Engelhardt
Harald
H
Abteilung Molekulare Strukturbiologie, Max-Planck-Institut für Biochemie, Am Klopferspitz 18, D-82152 Martinsried, Germany. engelhar@biochem.mpg.de
D001105:Archaea / Q000378:metabolism*; D019843:Archaeal Proteins / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry; D001703:Biophysics / Q000379:methods; D002462:Cell Membrane / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D019620:Desulfurococcaceae / Q000378:metabolism; D046911:Macromolecular Substances / Q000737:chemistry; D008954:Models, Biological; D008962:Models, Theoretical; D009995:Osmosis; D011312:Pressure; D011487:Protein Conformation; D013314:Stress, Mechanical; D014867:Water / Q000737:chemistry
D019843:Archaeal Proteins; D001426:Bacterial Proteins; D046911:Macromolecular Substances; D014867:Water