An acidic protein aligns magnetosomes along a filamentous structure in magnetotactic bacteria

  title={An acidic protein aligns magnetosomes along a filamentous structure in magnetotactic bacteria},
  author={Andr{\'e} Scheffel and Manuela Gruska and Damien Faivre and Alexandros A. Linaroudis and J{\"u}rgen M. Plitzko and Dirk Sch{\"u}ler},
Magnetotactic bacteria are widespread aquatic microorganisms that use unique intracellular organelles to navigate along the Earth's magnetic field. These organelles, called magnetosomes, consist of membrane-enclosed magnetite crystals that are thought to help to direct bacterial swimming towards growth-favouring microoxic zones at the bottom of natural waters. Questions in the study of magnetosome formation include understanding the factors governing the size and redox-controlled synthesis of… 

Genetics and cell biology of magnetosome formation in magnetotactic bacteria

A total of 28 conserved genes present in various magnetic bacteria were identified to be specifically associated with the magnetotactic phenotype, most of which are located in the genomic magnetosome island.

Genetics and cell biology of magnetosome formation in magnetotactic bacteria.

A total of 28 conserved genes present in various magnetic bacteria were identified to be specifically associated with the magnetotactic phenotype, most of which are located in the genomic magnetosome island.

The Bacterial Magnetosome: A Unique Prokaryotic Organelle

The bacterial magnetosome is a unique prokaryotic organelle comprising magnetic mineral crystals surrounded by a phospholipid bilayer membrane surrounding magnetic crystals of magnetite or greigite, which cause cells of magnetotactic bacteria to passively align and swim along the Earth's magnetic field lines.

From invagination to navigation: The story of magnetosome‐associated proteins in magnetotactic bacteria

The process in which the magnetosome is formed is described with an emphasis on the different proteins that participate in each stage of the magnetOSome formation scheme.

Overproduction of Magnetosomes by Genomic Amplification of Biosynthesis-Related Gene Clusters in a Magnetotactic Bacterium

It is demonstrated that the tuned expression of the mam and mms clusters provides a powerful strategy for the control of magnetosome size and number, thereby setting the stage for high-yield production of tailored magnetic nanoparticles by synthetic biology approaches.

A Bacterial Backbone: Magnetosomes in Magnetotactic Bacteria

Magnetosomes are intracellular, tens of nanometer-sized, membrane-bounded crystals of the magnetic minerals magnetite and greigite synthesized by a diverse group of prokaryotes termed the magnetotactic bacteria and possess novel magnetic properties that have been exploited in numerous applications and are important in biotechnology.

A Look into the Biochemistry of Magnetosome Biosynthesis in Magnetotactic Bacteria.

The current knowledge on magnetosome biosynthesis is presented with a focus on the different proteins and the main biochemical pathways along this process, including an ensemble of unique proteins that participate in different stages during magnetosomes formation.

Ecology, Diversity, and Evolution of Magnetotactic Bacteria

The purpose of this review is focused on the diversity and the ecology of the MTB and also the evolution and transfer of the molecular determinants involved in magnetosome formation.

Magnetosome chain superstructure in uncultured magnetotactic bacteria

An additional level of organization of the magnetosome chains in uncultured magnetotactic cocci found in marine and freshwater sediments is described and it is suggested that genetic determinants that are not present or active in bacteria with magnetosomes randomly rotated within a chain must be present in bacteria that organize magnetosites so precisely.

Segregation of prokaryotic magnetosomes organelles is driven by treadmilling of a dynamic actin-like MamK filament

A novel mechanism for prokaryotic organelle segregation is proposed that, similar to the type-II bacterial partitioning system of plasmids, relies on the action of cytomotive actin-like filaments together with specific connectors, which transport the magnetosome cargo in a fashion reminiscent of eukaryoticActin-organelle transport and segregation mechanisms.



Molecular analysis of a subcellular compartment: the magnetosome membrane in Magnetospirillum gryphiswaldense

Current research is directed towards the biochemical and genetic analysis of MMP functions in magnetite biomineralization as well as their expression and localization during growth.

Observations of Magnetosome Organization, Surface Structure, and Iron Biomineralization of Undescribed Magnetic Bacteria: Evolutionary Speculations

The presence of virtually identical magnetosome chains in the eukaryotes is consistent with an inheritance through the process of serial endosymbiosis, and for the geosciences, the magnetic bacteria provide an important supply of fine-grained magnetite to sediments, where they are often used to investigate the past history of the geomagnetic field.

Magnetosome vesicles are present before magnetite formation, and MamA is required for their activation.

Together, these results suggest that the magnetosome precisely coordinates magnetite biomineralization and can serve as a model system for the study of organelle biogenesis in noneukaryotic cells.

Electron microscopic studies of magnetosomes in magnetotactic bacteria

  • Dennis A. BazylinskiAnthony J. Garratt‐ReedRichard B. Frankel
  • Geology, Materials Science
    Microscopy research and technique
  • 1994
Electron microscopic studies on magnetosomes in magnetotactic bacteria have revealed much information on their composition, structure, and even the formation of their mineral phase. The mineral

Inactivation of the Flagellin Gene flaA in Magnetospirillum gryphiswaldense Results in Nonmagnetotactic Mutants Lacking Flagellar Filaments

The targeted disruption of the flagellin gene flaA was shown to eliminate flagella formation, motility, and magnetotaxis and will make it possible to take full advantage of the forthcoming genome sequences of M. gryphiswaldense and other magnetotactic bacteria.

A Hypervariable 130-Kilobase Genomic Region of Magnetospirillum gryphiswaldense Comprises a Magnetosome Island Which Undergoes Frequent Rearrangements during Stationary Growth

The data suggest that the genomic MAI undergoes frequent transposition events, which lead to subsequent deletion by homologous recombination under physiological stress conditions, which can be interpreted in terms of adaptation to physiological stress and might contribute to the genetic plasticity and mobilization of the magnetosome island.

Characterization of a Spontaneous Nonmagnetic Mutant of Magnetospirillum gryphiswaldense Reveals a Large Deletion Comprising a Putative Magnetosome Island

Findings suggest the existence of a putative large magnetosome island in M. gryphiswaldense and other magnetotactic bacteria.

Growth and magnetosome formation by microaerophilic Magnetospirillum strains in an oxygen-controlled fermentor

Media and growth conditions were optimized for the microaerobic cultivation of Magnetospirillum gryphiswaldense in flasks and in a fermentor, resulting in significantly increased cell and magnetosome yields, compared with earlier studies, and provide the basis for large-scale cultivation of magnetospirilla under defined conditions.

Magnetic Colloids from Magnetotactic Bacteria: Chain Formation and Colloidal Stability

Single-domain magnetite (Fe3O4) crystals, harvested from magnetotactic bacteria, display on transmission electron micrographs the cluster morphologies (folded chains, flux-closure rings) predicted

Biochemical and Proteomic Analysis of the Magnetosome Membrane in Magnetospirillum gryphiswaldense

Several magnetosome proteins found in Magnetospirillum gryphiswaldense display repetitive or highly acidic sequence patterns, which are known from other biomineralizing systems and thus may have relevance for magnetite formation.