Projection structures reveal the position of the DNA within DNA-Dps Co-crystals.
One of the universal mechanisms for the response of Escherichia coli to stress is the increase of the synthesis of specific histone-like proteins that bind the DNA, Dps. As a result, two-and three-dimensional crystalline arrays may be observed in the cytoplasm of starving cells. Here, we determined the conditions to obtain very thin two-dimensional DNA-Dps co-crystals in vitro, and studied their projection structures, using electron microscopy. Analysis of the projection maps of the free Dps crystals revealed two lattice types: hexagonal and rectangular. We used the fluorescently labeled DNA to prove that the DNA is present within the co-crystals with Dps in vitro, and visualized its position using transmission electron microscopy. Molecular modeling confirmed the DNA position within the crystal. We have also suggested a structural model for the DNA-Dps co-crystal dissolving in the presence of Mg2+ ions.
['Moiseenko|Andrey|A|', 'Loiko|Natalia|N|', 'Tereshkina|Ksenia|K|', 'Danilova|Yana|Y|', 'Kovalenko|Vladislav|V|', 'Chertkov|Oleg|O|', 'Feofanov|Alexey V|AV|', 'Krupyanskii|Yurii F|YF|', 'Sokolova|Olga S|OS|']
D001425:Bacterial Outer Membrane Proteins D002232:Carbocyanines D003460:Crystallization D004269:DNA, Bacterial D004926:Escherichia coli D029968:Escherichia coli Proteins D005456:Fluorescent Dyes D015870:Gene Expression D015636:Magnesium Chloride D046529:Microscopy, Electron, Transmission D008958:Models, Molecular D011485:Protein Binding D013194:Staining and Labeling
Escherichia coli Dps Electron microscopy Fluorescent microscopy Fourier transform Two-dimensional crystals