title: Common ancestry of iron oxide- and iron-sulfide-based biomineralization in magnetotactic bacteria.
abstract: Magnetosomes are prokaryotic organelles produced by magnetotactic bacteria that consist of nanometer-sized magnetite (Fe(3)O(4)) or/and greigite (Fe(3)S(4)) magnetic crystals enveloped by a lipid bilayer membrane. In magnetite-producing magnetotactic bacteria, proteins present in the magnetosome membrane modulate biomineralization of the magnetite crystal. In these microorganisms, genes that encode for magnetosome membrane proteins as well as genes involved in the construction of the magnetite magnetosome chain, the mam and mms genes, are organized within a genomic island. However, partially because there are presently no greigite-producing magnetotactic bacteria in pure culture, little is known regarding the greigite biomineralization process in these organisms including whether similar genes are involved in the process. Here using culture-independent techniques, we now show that mam genes involved in the production of magnetite magnetosomes are also present in greigite-producing magnetotactic bacteria. This finding suggest that the biomineralization of magnetite and greigite did not have evolve independently (that is, magnetotaxis is polyphyletic) as once suggested. Instead, results presented here are consistent with a model in which the ability to biomineralize magnetosomes and the possession of the mam genes was acquired by bacteria from a common ancestor, that is, the magnetotactic trait is monophyletic.
authors.affiliation: Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Abreu
authors.forename: Mauricio E
authors.initials: ME
authors.lastname: Cantão
authors.forename: Marisa F
authors.initials: MF
authors.lastname: Nicolás
authors.forename: Fernando G
authors.initials: FG
authors.lastname: Barcellos
authors.forename: Viviana
authors.initials: V
authors.lastname: Morillo
authors.forename: Luiz Gp
authors.initials: LG
authors.lastname: Almeida
authors.forename: Fabrícia F
authors.initials: FF
authors.lastname: do Nascimento
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Lefèvre
authors.forename: Dennis A
authors.initials: DA
authors.lastname: Bazylinski
authors.forename: Ana Tereza
authors.initials: AT
authors.lastname: R de Vasconcelos
authors.forename: Ulysses
authors.initials: U
authors.lastname: Lins
mesh_terms: D001419:Bacteria / Q000737:chemistry / Q000166:cytology* / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D052203:Ferrosoferric Oxide / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D008280:Magnetics; D055944:Magnetosomes; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D015388:Organelles / Q000235:genetics / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D013440:Sulfides; C111959:greigite; D007501:Iron; D052203:Ferrosoferric Oxide