title: The role of heme binding by DNA-protective protein from starved cells (Dps) in the Tolerance of Porphyromonas gingivalis to heme toxicity.
abstract: The widely expressed DNA-protective protein from starved-cells (Dps) family proteins are considered major contributors to prokaryotic resistance to stress. We show here that Porphyromonas gingivalis Dps (PgDps), previously described as an iron-storage and DNA-binding protein, also mediates heme sequestration. We determined that heme binds strongly to PgDps with an apparent K(d) of 3.7 × 10(-8) m and is coordinated by a single surface-located cysteine at the fifth axial ligand position. Heme and iron sequestered in separate sites by PgDps provide protection of DNA from H(2)O(2)-mediated free radical damage and were found to be important for growth of P. gingivalis under excess heme as the only iron source. Conservation of the heme-coordinating cysteine among Dps isoforms from the Bacteroidales order suggests that this function may be a common feature within these anaerobic bacteria.
authors.affiliation: University of Sydney, New South Wales 2006, Australia.
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Gao
authors.forename: Yanling
authors.initials: Y
authors.lastname: Lu
authors.forename: Gina
authors.initials: G
authors.lastname: Browne
authors.forename: Benjamin C-M
authors.initials: BC
authors.lastname: Yap
authors.forename: Jill
authors.initials: J
authors.lastname: Trewhella
authors.forename: Neil
authors.initials: N
authors.lastname: Hunter
authors.forename: Ky-Anh
authors.initials: KA
authors.lastname: Nguyen
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage / Q000187:drug effects* / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000502:physiology; D006418:Heme / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007501:Iron / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology; D016966:Porphyromonas gingivalis / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C083911:DPS protein, Bacteria; D016877:Oxidants; D020033:Protein Isoforms; D006418:Heme; D006861:Hydrogen Peroxide; D007501:Iron