English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

The cell envelope of the hyperthermophilic archaebacterium Pyrobaculum organotrphum consists of two regularly arrayed protein layers: three-dimensional structure of the outer layer

MPS-Authors
There are no MPG-Authors in the publication available
External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Phipps, B. M., Huber, R., & Baumeister, W. (1991). The cell envelope of the hyperthermophilic archaebacterium Pyrobaculum organotrphum consists of two regularly arrayed protein layers: three-dimensional structure of the outer layer. Molecular Microbiology., 5(2), 253-265.


Cite as: https://hdl.handle.net/11858/00-001M-0000-0010-7447-C
Abstract
The cell envelope of the hyperthermophilic sulphur-reducing archaebacterium Pyrobaculum organotrophum H10 was found to be composed of two distinct hexagonally arranged crystalline protein arrays. Electron microscopic analysis of freeze-etched cells and isolated envelopes in conjunction with image processing showed that the inner layer (lattice centre-to-centre spacing 27.9 nm) is essentially identical to the protein array of Pyrobaculum islandicum GEO3, a complex, rigid structure implicated in the maintenance of cell shape. The outer layer has clear p6 symmetry and a lattice spacing of 20.6 nm. Its three-dimensional structure was reconstructed from a negative stain tilt series of an intact double-layered envelope using Fourier filtration to separate the desired information from the other lattices present. The outer layer is a unique, porous network of blocklike dimers disposed around six-fold axes, and exhibits minimal asymmetry between its inner and outer faces. It appears to be rather loosely associated with the outer surface of the inner layer. In most H10 envelopes, the inner layer is orientated with one base vector exactly perpendicular to the long axis of the cell, so that the cylindrical portion is composed of a series of parallel cell-girdling hoops of hexameric morphological units. All the other known Pyrobaculum strains were found to have a GEO3-type envelope structure, consisting of a single rigid protein array and a fibrous capsule. Although H10 does not possess a capsule, fibrils appear to be sandwiched between the two protein layers.