Dps (DNA-binding protein from starved cells) is well known for the structural protection of bacterial DNA by the formation of highly ordered intracellular assemblies under stress conditions. Moreover, this ferritin-like protein can perform fast oxidation of ferrous ions and subsequently accumulate clusters of ferric ions in its nanocages, thus providing the bacterium with physical and chemical protection. Here, cryo-electron microscopy was used to study the accumulation of iron ions in the nanocage of a Dps protein from Escherichia coli. We demonstrate that Fe²⁺ concentration in the solution and incubation time have an insignificant effect on the volume and the morphology of iron minerals formed in Dps nanocages. However, an increase in the Fe²⁺ level leads to an increase in the proportion of larger clusters and the clusters themselves are composed of discrete ~1–1.5 nm subunits.

The Dps protein (a DNA-binding protein from starving cells) is well known for its ability to protect cells from various negative factors, including oxidati

The oligomeric state of the nucleoid-associated protein IHF (integration host factor) plays a significant role in the organization and compaction of the bacterial nucleoid and also in the evolution of bacterial resistance to unfavorable environmental conditions, in particular to antibiotics. Although IHF was identified more than 25 years ago, the molecular mechanisms of its participation in these processes are poorly understood. Using small-angle X-ray scattering, it was demonstrated for the first time that there are different oligomeric states of IHF in an aqueous medium depending on the presence of metal cations. It was found that the presence of Mg²⁺ and K⁺ ions hinders the formation of high-order oligomers of IHF. The results of this study may be useful in the development of strategies against bacterial resistance to drugs.