title: Cryo-electron tomography of the magnetotactic vibrio Magnetovibrio blakemorei: insights into the biomineralization of prismatic magnetosomes.
abstract: We examined the structure and biomineralization of prismatic magnetosomes in the magnetotactic marine vibrio Magnetovibrio blakemorei strain MV-1 and a non-magnetotactic mutant derived from it, using a combination of cryo-electron tomography and freeze-fracture. The vesicles enveloping the Magnetovibrio magnetosomes were elongated and detached from the cell membrane. Magnetosome crystal formation appeared to be initiated at a nucleation site on the membrane inner surface. Interestingly, while scattered filaments were observed in the surrounding cytoplasm, their association with the magnetosome chains could not be unequivocally established. Our data suggest fundamental differences between prismatic and octahedral magnetosomes in their mechanisms of nucleation and crystal growth as well as in their structural relationships with the cytoplasm and plasma membrane.
authors.affiliation: Instituto de Microbiologia Paulo de Góes, CCS, Bloco I, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-590, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Abreu
authors.forename: Alioscka A
authors.initials: AA
authors.lastname: Sousa
authors.forename: Maria A
authors.initials: MA
authors.lastname: Aronova
authors.forename: Youngchan
authors.initials: Y
authors.lastname: Kim
authors.forename: Daniel
authors.initials: D
authors.lastname: Cox
authors.forename: Richard D
authors.initials: RD
authors.lastname: Leapman
authors.forename: Leonardo R
authors.initials: LR
authors.lastname: Andrade
authors.forename: Bechara
authors.initials: B
authors.lastname: Kachar
authors.forename: Dennis A
authors.initials: DA
authors.lastname: Bazylinski
authors.forename: Ulysses
authors.initials: U
authors.lastname: Lins
mesh_terms: D020285:Cryoelectron Microscopy; D003460:Crystallization / Q000379:methods*; D055032:Electron Microscope Tomography; D005614:Freeze Fracturing; D055944:Magnetosomes / Q000502:physiology* / Q000648:ultrastructure*; D012244:Rhodospirillaceae / Q000648:ultrastructure*