title: Overexpression and characterization of an iron storage and DNA-binding Dps protein from Trichodesmium erythraeum.
abstract: Although the role of iron in marine productivity has received a great deal of attention, no iron storage protein has been isolated from a marine microorganism previously. We describe an Fe-binding protein belonging to the Dps family (DNA binding protein from starved cells) in the N(2)-fixing marine cyanobacterium Trichodesmium erythraeum. A dps gene encoding a protein with significant levels of identity to members of the Dps family was identified in the genome of T. erythraeum. This gene codes for a putative Dps(T. erythraeurm) protein (Dps(tery)) with 69% primary amino acid sequence similarity to Synechococcus DpsA. We expressed and purified Dps(tery), and we found that Dps(tery), like other Dps proteins, is able to bind Fe and DNA and protect DNA from degradation by DNase. We also found that Dps(tery) binds phosphate, like other ferritin family proteins. Fe K near-edge X-ray absorption of Dps(tery) indicated that it has an iron core that resembles that of horse spleen ferritin.
authors.affiliation: Department of Chemistry, Princeton University, 153A Guyot Hall, Princeton, NJ 08540, USA. mcastrui@princeton.edu
authors.forename: M
authors.initials: M
authors.lastname: Castruita
authors.forename: M
authors.initials: M
authors.lastname: Saito
authors.forename: P C
authors.initials: PC
authors.lastname: Schottel
authors.forename: L A
authors.initials: LA
authors.lastname: Elmegreen
authors.forename: S
authors.initials: S
authors.lastname: Myneni
authors.forename: E I
authors.initials: EI
authors.lastname: Stiefel
authors.forename: F M M
authors.initials: FM
authors.lastname: Morel
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000458:Cyanobacteria / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000032:analysis / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D008969:Molecular Sequence Data; D012623:Seawater / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C083911:DPS protein, Bacteria; D007501:Iron