The interaction of manganese ions with DNA

In Situ Determination of Manganese(II) Speciation in Deinococcus radiodurans by High Magnetic Field EPR

“…Nucleotides in the form of DNA are also present in a high concentration, and isolated D. radiodurans DNA has been found to contain significant amounts of Mn(II) (5). Crystallographic studies show that the Mn(II) can bind to DNA directly to phosphate backbone or the N-7 of atoms of guanosines or indirectly to the phosphates through intervening water molecules (33,34). The large observed 31 P coupling in the cell ENDOR spectra is consistent with direct binding to phosphate groups.…”

Synthesis of a DNA–Silica Complex with Rare Two‐Dimensional Square p4mm Symmetry

“…A small DNA-DNA interaxial separation would be obtained at higher concentrations by the formation of an electrostatic "zipper" (II-III) with interactions between the negatively charged strands and positively charged grooves of opposing molecules. [13][14][15][16] An ideal zipper requires the mutual azimuthal orientation to be 72-1088. This angle can be obtained in geometrical calculations based on the B-DNA structure when the two strands are separated by an azimuthal angle of about 1448 (Supporting Information, Figure S9).…”

“…By exploiting the cooperative effects of a quaternary ammonium silane, which acts both as a DNA condensing agent through the positively charged quaternary ammonium group and stabilizes silica mineralization by co-condensing with the silica source, p4mm and 2D hexagonal p6mm DSCs were synthesized at different DNA concentrations, giving rise to a new DNA LC phase diagram. According to the results of simulations based on Kornyshev-Leikin theory [13,14] and previous reports on cation-crystallized DNA, [9,15,16] the small interaxial separation of about 25 formed upon quaternary ammonium phosphate electrostatic "zipping" along the DNA-DNA contacts and the silica wall formed between DNA strands in diagonal positions are considered to be optimal for formation of the p4mm structure.In general, DNA is not capable of directing surface deposition of silica to form a DNA-silica complex because silicate is negatively charged in the pH range of 4.3-11.9 needed to maintain the double-helix configuration of DNA.[17] Here we attempted to synthesize a DSC by using the cooperative effects of N-trimethoxysilylpropyl-N,N,Ntrimethylammonium chloride (TMAPS).[18] The positively charged quaternary ammonium group acts as a condensing agent for DNA, and the silane site is co-condensed with a silica source, for example, tetraethoxysilane (TEOS), for subsequent assembly of the silica framework. The trimethylene groups of TMAPS covalently tether the silicon atoms incorporated into the framework to the cationic ammonium groups regardless of the type of charge on the silicate.…”

Structure of the tetradecanucleotide d(CCCCGGTACCGGGG)2as an A-DNA duplex

“…In B-type duplexes, for example the oligonucleotide d(CGTTAA-TTAACG) 2 crystallized in the presence of Mn 2+ (10 mM) and a low spermine concentration (0.25 mM) (Millonig et al, 2009), the ions form direct bridges between neighbouring duplexes in the crystal. However, this type of direct bridging is absent in the present A-type duplex.…”