Other DNA compounds...

[Externet]

Good day.

In addition to GATC , is there other 'filler' compounds lodged between them, and other variations different than sugar phosphate constituting the 'back bone' shown here, or eventual contaminants to the purity of any of these components ?

[CharonY]

Generally speaking no- DNA is a polymer consisting of nucleotide subunits. Each nucleotide consists of deoxyribose (the pentose sugar), a phosphate group and a base.

That being said, some parts of the DNA can be modified by adding e.g. a methyl group. In vivo there is also water, but that is not really part of the DNA structure. If you are thinking of "filler" because the image makes it look that there is a lot of space there, this is in large part due to the schematic nature of the image. If you do an xray of a DNA crystal, you do not have a lot of space, the base stacks are sitting quite neatly on top of each other.