• Shtykova, Eleonora
• Vasiliev, Alexander
• Chesnokov, Yury
• Gruzinov, Andrey
• Mozhaev, Andrey
• Matveev, Vladimir
• Dadinova, Liubov

Abstract

International journal of molecular sciences 22(11), 6056 (1-12) (2021). doi:10.3390/ijms22116056 ... : 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$^{2+}$ 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$^{2+}$ 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 ...

Topics

• Magnesium
• Magnesium
• electron microscopy
• iron
• small angle x-ray scattering