title: Structure and membrane affinity of new amphiphilic siderophores produced by Ochrobactrum sp. SP18.
abstract: The coastal alpha-proteobacterium Ochrobactrum sp. SP18 produces a suite of three citrate-derived, cell-associated amphiphilic siderophores, ochrobactins A-C. The ochrobactins are composed of a citric acid backbone amide-linked to two lysine residues. Each epsilon-amine of lysine is hydroxylated and acylated forming two hydroxamic acid moieties. One of the acylated appendages of each ochrobactin is (E)-2-decenoic acid. The other acylated appendages for ochrobactins A-C are (E)-2-octenoic acid, octanoic acid and (E)-2-decenoic acid, respectively. The ferric ochrobactin complexes are photoreactive in UV light, producing an oxidized ligand with loss of 46 mass units that can still coordinate Fe(III). The relative partitioning of the apo-ochrobactins, Fe(III) ochrobactins and Fe(III) photoproducts into 1,2-dimyristoyl-sn-glycero-3-phosphocholine vesicles is presented. The ochrobactins are the first example of aerobactin-based siderophores with two fatty acid appendages produced in a suite with varying acyl appendage lengths.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106-9510, USA.
authors.forename: Jessica D
authors.initials: JD
authors.lastname: Martin
authors.forename: Yusai
authors.initials: Y
authors.lastname: Ito
authors.forename: Vanessa V
authors.initials: VV
authors.lastname: Homann
authors.forename: Margo G
authors.initials: MG
authors.lastname: Haygood
authors.forename: Alison
authors.initials: A
authors.lastname: Butler
mesh_terms: D000107:Acetylation; D019343:Citric Acid / Q000032:analysis; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D008027:Light; D008239:Lysine / Q000032:analysis; D008566:Membranes / Q000737:chemistry; D015394:Molecular Structure; D042041:Ochrobactrum / Q000145:classification / Q000378:metabolism*; D010777:Photochemistry; D010802:Phylogeny; D017262:Siderophores / Q000737:chemistry* / Q000302:isolation & purification; D014466:Ultraviolet Rays
chemical_list: D017262:Siderophores; D019343:Citric Acid; D007501:Iron; D008239:Lysine; D004134:Dimyristoylphosphatidylcholine