title: Tertiary structure of bacterial murein: the scaffold model.
abstract: Although the chemical structure and physical properties of peptidoglycan have been elucidated for some time, the precise three-dimensional organization of murein has remained elusive. Earlier published computer simulations of the bacterial murein architecture modeled peptidoglycan strands in either a regular (D. Pink, J. Moeller, B. Quinn, M. Jericho, and T. Beveridge, J. Bacteriol. 182: 5925-5930, 2000) or an irregular (A. Koch, J. Theor. Biol. 204: 533-541, 2000) parallel orientation with respect to the plasma membrane. However, after integrating published experimental data on glycan chain length distribution and the degree of peptide side chain cross-linking into this computer simulation, we now report that the proposed planar network of murein appears largely dysfunctional. In contrast, a scaffold model of murein architecture, which assumes that glycan strands extend perpendicularly to the plasma membrane, was found to accommodate published experimental evidence and yield a viable stress-bearing matrix. Moreover, this model is in accordance with the well-established principle of murein assembly in vivo, i.e., sequential attachment of strands to the preexisting structure. For the first time, the phenomenon of division plane alternation in dividing bacteria can be reconciled with a computer model of the molecular architecture of murein.
authors.affiliation: N. F. Gamaleya Institute for Epidemiology and Microbiology, Moscow, Russia.
authors.forename: Boris A
authors.initials: BA
authors.lastname: Dmitriev
authors.forename: Filip V
authors.initials: FV
authors.lastname: Toukach
authors.forename: Klaus-Jürgen
authors.initials: KJ
authors.lastname: Schaper
authors.forename: Otto
authors.initials: O
authors.lastname: Holst
authors.forename: Ernst T
authors.initials: ET
authors.lastname: Rietschel
authors.forename: Stefan
authors.initials: S
authors.lastname: Ehlers
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D002236:Carbohydrate Conformation; D003198:Computer Simulation; D003432:Cross-Linking Reagents; D008958:Models, Molecular; D010457:Peptidoglycan / Q000737:chemistry* / Q000378:metabolism
chemical_list: D003432:Cross-Linking Reagents; D010457:Peptidoglycan