Crystalline Bacterial Cell Surface Layers

Crystalline surface layers (S-layers) represent an almost universal feature of archaebacterial cell envelopes and can be found in gram-positive and gram-negative eubacterial species from nearly all phylogenetic branches. S-layers consist of a single protein- or glycoprotein species and thus can be considered as one of the most primitive membrane structures developed during evolution. Prokaryotes carrying S-layers are ubiquitously found in every part of the biosphere. This supports the concept of a general supramolecular "porous crystalline surface layer" fulfilling a broad spectrum of functions which are strongly dependent on the particular environmental and ecological conditions. Their structural simplicity makes S-layers a suitable model for analyzing structure-function relationships as well as dynamic aspects of membrane morphogenesis.

From the contents: Comparative Chemistry of the Rigid Cell Wall Component and its Phylogenetic Implications.- Evidence for the Glycoprotein Nature of Eubacterial S-Layers.- Thermoresistance of A-Layer-Deficient Mutants of Aeromonas salmonicida.- The Three-Dimensional Structure of Bacterial Surface Layers.- The Surface Protein of the Archaebacterium Thermoproteus tenax.- Three-Dimensional Structure of the Regular Tetragonal Surface Layer of Azotobacter vinelandii.- Occurrence and Characterization of S-Layers in Oral Bacteria.- S-Layers in Cyanobacteria.- Cloning and Sequencing of the S-Layer Glycoprotein Gene of Halobacterium halobium- Comparative Studies on Synthetic and S-Layer Ultrafiltration Membranes.- Appendix: Crystalline Surface Layers on Bacteria.