Biocrystallization in Bacterial and Fungal Cells and Spores

Resumo

A series of X-ray diffraction experiments were performed for the first time to study stress-induced biocrystallization (structural response to stress) in the bacteria E. coli, the spore-forming bacteria Bacillus cereus, and in cells and spores of the mycelial fungus Umbelopsis ramanniana. High-intensity areas with spacings of 90 and 44 Å are indicative of a periodically ordered arrangement (most likely nanocrystalline) of the bacterial nucleoid. For the starved bacteria Bacillus cereus, a peak at a spacing of 45 Å is also assigned to nanocrystalline complexes of DNA with the Dps protein. The spores of the fungus Umbelopsis ramanniana VKM F-582, as well as the spores of Bacillus cereus, form ordered arrays of DNA molecules with DNA-condensing acid-soluble proteins SASPs. Starved dehydrated mycelial cells of the fungus Umbelopsis ramanniana form ordered structures with spacings from 27 to 55 Å. A series of peaks reflect the formation of a number of ordered protein arrays, apparently with DNA, with continuously varying characteristic interplanar spacings.