The order, or sequence, nucleic acids are assembled in provides the key to understanding a microbe's DNA. The DNA is what gives the microbe it's identity. It provides the key to understanding what the microbe is, how it functions, what it does in terms of life functions, and the conditions under which it thrives. Once we understand all that, we can organize the microbe into a carefully constructed level of identification, generally called taxonomy.
Nucleic acids have the general molecular composition of a sugar, a phosphate, and one of the four bases, those being adenine, guanine, thymine, and cytosine. The correct pairing to construct a strand of DNA from these selections is adenine will pair to thymine, while cytosine will pair to guanine (A-T, C-G). The assembly of these nucleic acids has a direct impact on the taxonomic classification of the microbe, as it places it into separate, distinct categories.