title: S-layer nanoglycobiology of bacteria.
abstract: Cell surface layers (S-layers) are common structures of the bacterial cell envelope with a lattice-like appearance that are formed by a self-assembly process. Frequently, the constituting S-layer proteins are modified with covalently linked glycan chains facing the extracellular environment. S-layer glycoproteins from organisms of the Bacillaceae family possess long, O-glycosidically linked glycans that are composed of a great variety of sugar constituents. The observed variations already exceed the display found in eukaryotic glycoproteins. Recent investigations of the S-layer protein glycosylation process at the molecular level, which has lagged behind the structural studies due to the lack of suitable molecular tools, indicated that the S-layer glycoprotein glycan biosynthesis pathway utilizes different modules of the well-known biosynthesis routes of lipopolysaccharide O-antigens. The genetic information for S-layer glycan biosynthesis is usually present in S-layer glycosylation (slg) gene clusters acting in concert with housekeeping genes. To account for the nanometer-scale cell surface display feature of bacterial S-layer glycosylation, we have coined the neologism 'nanoglycobiology'. It includes structural and biochemical aspects of S-layer glycans as well as molecular data on the machinery underlying the glycosylation event. A key aspect for the full potency of S-layer nanoglycobiology is the unique self-assembly feature of the S-layer protein matrix. Being aware that in many cases the glycan structures associated with a protein are the key to protein function, S-layer protein glycosylation will add a new and valuable component to an 'S-layer based molecular construction kit'. In our long-term research strategy, S-layer nanoglycobiology shall converge with other functional glycosylation systems to produce 'functional' S-layer neoglycoproteins for diverse applications in the fields of nanobiotechnology and vaccine technology. Recent advances in the field of S-layer nanoglycobiology have made our overall strategy a tangible aim of the near future.
authors.affiliation: Universität für Bodenkultur Wien, Zentrum für NanoBiotechnologie A-1180 Wien, Gregor-Mendel-Strasse 33, Austria. paul.messner@boku.ac.at
authors.forename: Paul
authors.initials: P
authors.lastname: Messner
authors.forename: Kerstin
authors.initials: K
authors.lastname: Steiner
authors.forename: Kristof
authors.initials: K
authors.lastname: Zarschler
authors.forename: Christina
authors.initials: C
authors.lastname: Schäffer
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry; D001419:Bacteria / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry; D005798:Genes, Bacterial / Q000502:physiology; D054794:Glycomics / Q000379:methods*; D006031:Glycosylation; D008562:Membrane Glycoproteins / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D008562:Membrane Glycoproteins; C055764:S-layer proteins