title: The cell wall structure of a magnesium-dependent halobacterium, Halobacterium volcanii CD-2, from the Dead Sea.
abstract: Cell wall preparations from the magnesium-dependent halophilic bacterium, Halobacterium volcanii, were studied by high-resolution electron microscopy complemented with image analysis and processing. For ultrastructural studies, specimens were prepared by a variety of methods, including negative staining, and metal shadowing after air-drying, freeze-drying, or freeze-fracturing and etching. All methods revealed the cell wall to be composed of a near-hexagonal lattice of unit cells having a center-to-center spacing of 15.5 nm. While negatively stained samples yielded two types variably revealed the unit cell to be composed of six protomers surrounding a central mass depression. This low-resolution unit cell morphology appears very similar to that of other bacterial cell wall S-layers studied to date.
authors.affiliation: Department of Cell Biology and Anatomy, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
authors.forename: M
authors.initials: M
authors.lastname: Kessel
authors.forename: E L
authors.initials: EL
authors.lastname: Buhle
authors.forename: S
authors.initials: S
authors.lastname: Cohen
authors.forename: U
authors.initials: U
authors.lastname: Aebi
mesh_terms: D002473:Cell Wall / Q000648:ultrastructure*; D006217:Halobacterium / Q000378:metabolism / Q000648:ultrastructure*; D008274:Magnesium / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning
chemical_list: D008274:Magnesium