Harnessing DNA Binding Proteins from Starved Cells for DNA Origami Protection

DNA origami is an attractive method for building structurally versatile and addressable nanostructures for diverse applications. The structural integrity of DNA, however, is rather limited in application-relevant environments, such as in low-magnesium, nuclease-rich, and oxidative conditions. In nature, bacteria protect their genome against different stress factors by producing DNA-binding proteins from starved cells (Dps). The protective function of Dps relies on its ability to bind DNA into highly ordered crystalline structures and on its role as an iron storage and oxidation center that prevents the formation of damaging radicals. Here, the hierarchical assembly of Escherichia coli Dps with DNA origami via electrostatic interactions is demonstrated. The assembly properties were studied with various DNA origami shapes under different ionic strengths. The results indicate that the formation of highly ordered structures is dependent on the origami morphology and show that the degree of order is improved by decreasing the assembly kinetics through increasing the ionic strength of the buffer. Furthermore, the co-assembly enhances the origami stability under oxidative stress. These results show the suitability of DNA origami in guiding the ordered assembly of nanostructures. Moreover, they provide an insight into improving DNA origami stability under challenging conditions.