title: Identification of iron transporters expressed in the magnetotactic bacterium Magnetospirillum magnetotacticum.
abstract: The magnetotactic bacterium Magnetospirillum magnetotacticum MS-1 mineralizes the magnetite (Fe(3)O(4)) crystal and organizes a highly ordered intracellular structure, called the magnetosome. However, the iron transport system, which supports the biogenesis of magnetite, is not fully understood. In this study, we first identified the expressions of both the ferric and the ferrous iron transporter proteins in M. magnetotacticum. The cellular protein compositions of ferric and ferrous iron-rich cultures were examined using two-dimensional electrophoresis. According to the gel patterns, two outer-membrane ferric-siderophore receptor homologues were identified as proteins strongly induced in the ferrous iron-rich condition. Also, we identified for the first time that the ferrous iron transport protein, FeoB, is expressed in the M. magnetotacticum cytoplasmic membrane using immunoblotting.
authors.affiliation: Department of Life Science, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Japan.
authors.forename: Azuma
authors.initials: A
authors.lastname: Taoka
authors.forename: Chihiro
authors.initials: C
authors.lastname: Umeyama
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Fukumori
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D052203:Ferrosoferric Oxide / Q000378:metabolism*; D015870:Gene Expression; D008280:Magnetics; D042201:Magnetospirillum / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008970:Molecular Weight; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D027682:Cation Transport Proteins; D011956:Receptors, Cell Surface; C035902:siderophore receptors; D052203:Ferrosoferric Oxide