Nucleotide Analogs

Nucleotides are building blocks of nucleic acids DNA and RNA, and serve as cofactors in sugar and lipid metabolism, in polyamine biosynthesis, in methylation reactions, and as carriers of energy. They are also constituents of the redox coenzymes, NAD(P) and FAD, and of signal molecules such as (p)ppGpp, which is involved in coordinating RNA synthesis with protein synthesis. Nucleotides are composed of a nitrogenous base, a five-carbon sugar (ribose or deoxyribose), and at least one phosphate group. Thus a nucleoside plus a phosphate group yields a nucleotide. The nucleotides are either ribo- or deoxyribonucleotides, and they are found either as mono-, di-, or triphosphates. Nucleoside triphosphates (ATP, GTP, CTP and UTP), play a central role in cell metabolism.