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-Structure paper
Title | Structural Rearrangement of Dps-DNA Complex Caused by Divalent Mg and Fe Cations. |
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Journal, issue, pages | Int J Mol Sci, Vol. 22, Issue 11, Year 2021 |
Publish date | Jun 3, 2021 |
Authors | Liubov Dadinova / Roman Kamyshinsky / Yury Chesnokov / Andrey Mozhaev / Vladimir Matveev / Andrey Gruzinov / Alexander Vasiliev / Eleonora Shtykova / |
PubMed Abstract | Two independent, complementary methods of structural analysis were used to elucidate the effect of divalent magnesium and iron cations on the structure of the protective Dps-DNA complex. Small-angle ...Two independent, complementary methods of structural analysis were used to elucidate the effect of divalent magnesium and iron cations on the structure of the protective Dps-DNA complex. Small-angle X-ray scattering (SAXS) and cryo-electron microscopy (cryo-EM) demonstrate that Mg ions block the N-terminals of the Dps protein preventing its interaction with DNA. Non-interacting macromolecules of Dps and DNA remain in the solution in this case. The subsequent addition of the chelating agent (EDTA) leads to a complete restoration of the structure of the complex. Different effect was observed when Fe cations were added to the Dps-DNA complex; the presence of Fe in solution leads to the total complex destruction and aggregation without possibility of the complex restoration with the chelating agent. Here, we discuss these different responses of the Dps-DNA complex on the presence of additional free metal cations, investigating the structure of the Dps protein with and without cations using SAXS and cryo-EM. Additionally, the single particle analysis of Dps with accumulated iron performed by cryo-EM shows localization of iron nanoparticles inside the Dps cavity next to the acidic (hydrophobic) pore, near three glutamate residues. |
External links | Int J Mol Sci / PubMed:34205216 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.2 Å |
Structure data | EMDB-12961: |
Source |
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