title: Three-dimensional reconstruction of the sevenfolded form of Bacillus subtilis Gro EL Chaperonin.
abstract: Bacillus subtilis grown at 42 degrees C produces a major form of Gro EL-like chaperonin that has been analyzed by electron microscopy. Most of the views show a clear sevenfold symmetry when studied by rotational analysis. The particles were classified into defined families by multivariate analysis and supervised fuzzy-set classification methods, and those belonging to a sevenfold family were averaged to produce a two-dimensional representative projection. These selected particles were then used, when titled by 55 degrees in the microscope goniometer stage, as the starting projections for a three-dimensional reconstruction protocol based on the random conical tilt series method. The resulting reconstruction shows the Gro EL-like chaperonin from B. subtilis as a cylindrical body with seven well defined lobules arranged almost parallel to the longitudinal axis of the particle. There is a channel that is placed along this axis and appears fully open in both sides. The geometry of the channel is polar and presents differences in both faces of the particle.
authors.affiliation: Centro de Biología Molecular (CSIC-UAM), Universidad Autónoma de Madrid, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Carrascosa
authors.forename: G
authors.initials: G
authors.lastname: Abella
authors.forename: S
authors.initials: S
authors.lastname: Marco
authors.forename: J M
authors.initials: JM
authors.lastname: Carazo
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000648:ultrastructure*; D018834:Chaperonin 60; D018833:Chaperonins; D004591:Electrophoresis, Polyacrylamide Gel; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000648:ultrastructure*; D008854:Microscopy, Electron; D008961:Models, Structural; D014176:Protein Biosynthesis; D011487:Protein Conformation; D011506:Proteins / Q000302:isolation & purification / Q000648:ultrastructure*
chemical_list: D001426:Bacterial Proteins; D018834:Chaperonin 60; D006360:Heat-Shock Proteins; D011506:Proteins; D018833:Chaperonins