nucleotidesadenine

An adenine nucleotide is a nucleotide that contains the purine base adenine. The most common examples in biology are the ribonucleotides AMP, ADP, and ATP, and their deoxy counterparts dAMP, dADP, and dATP. Each molecule consists of the adenine base linked to a sugar (ribose in RNA, deoxyribose in DNA) and a chain of one to three phosphate groups. The energy-rich triphosphate form (ATP) stores energy in its phosphoanhydride bonds and can transfer that energy to drive cellular processes.

ATP, ADP, and AMP play central roles in energy metabolism. ATP is hydrolyzed to ADP or to AMP to release usable energy; cells regenerate ATP from ADP and phosphate via cellular respiration and, in plants and algae, photosynthesis. Adenosine monophosphate is also interconverted through phosphorylation reactions, and collectively these nucleotides contribute to the cellular energy charge. Adenosine monophosphate can also be converted to cyclic AMP (cAMP), a second messenger involved in signal transduction.

In nucleic acid biology, the ribonucleotides and deoxyribonucleotides containing adenine serve as substrates for RNA and DNA synthesis. dNTPs (such as dATP) are incorporated into DNA by polymerases, while NTPs (such as ATP and GTP) supply RNA synthesis and energy. Adenine-containing nucleotides are maintained by salvage pathways and regulated by kinases and phosphatases. Besides energy and information transfer, adenine-containing dinucleotides (e.g., NAD+) participate in redox reactions and metabolism.