Deoxyribonucleic acid or DNA is a nucleic acid formed by deoxyribonucleotides, which are in turn made out of a phosphate group, deoxyribose (sugar) and a nitrogenous base (adenine, cytosine, guanine or timine). The genetic information of all cellular life on Earth is stored as DNA. Along with proteins, enzymes and RNA, DNA can be replicated, transcribed, tranlated or edited.
Within cells, DNA is synthesized from its NTP precursors and DNA polymerase III. For example, to add adenine, ATP is used. DNA polymerase III uses the same mechanism as other polymerases to add nucleotides: an associated magnesium ion deprotonates the 3’-OH residue, which in turn makes a nucleophilic attack in the α-phosphate of the NTP. As a result, a pyrophosphate group is released in an overall exergonic reaction.
- David L. Nelson, Michael M. Cox. Lehninger. Principles of Biochemistry. Sixth Edition.