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The Central Role of DNA: New Vistas in Microbial Biotechnology, Page 1 of 2
< Previous page Next page > /docserver/preview/fulltext/10.1128/9781555817855/9781555812645_Chap23-1.gif /docserver/preview/fulltext/10.1128/9781555817855/9781555812645_Chap23-2.gifAbstract:
This chapter talks about how DNA performs its important role and how it can be used for genetic engineering. Some understanding of DNA structure is essential for even an elementary appreciation of the exquisite mechanisms involved in gene action. DNA is a large macromolecule composed of three kinds of chemical units that are arranged in a very specific manner. Two of these units provide the backbone of DNA in the form of a two-stranded helix, in which two coiled fibers are connected. The two backbones of DNA are held together by pairs of nucleic acid bases. These bases represent the third kind of unit in DNA and consist of four types of small nitrogen-containing molecules that have distinctive chemical properties: adenine (A), thymine (T), guanosine (G), and cytosine (C). The identification of DNA as the genetic material in 19443 and the rapid development of bacterial genetics starting about 1950 were the beginnings of a great new wave of discoveries that opened unexpected vistas in microbial biotechnology. There is general agreement that recombinant DNA technology is capable of producing many new and useful drugs, industrial solvents, fertilizers, and so on. Determination of the complete genome sequences of many different kinds of microbes has another important purpose, namely, to aid in analysis of the course of evolution of life on Earth. Detailed comparisons of the DNA base sequences in microbes of diverse physiological capabilities are certain to reveal much about their evolutionary relationships.