Functions of Nucleotides
Function
Selected Examples
1. Energy metabolism
ATP (muscle contraction; active transport; ion
gradients; phosphate donor)
2. Monomeric units of nucleic acids
NTPs and dNTPs (substrates for RNA and DNA)
3. Physiological mediators
Adenosine (coronary blood flow); ADP (platelet
aggregation); cAMP and cGMP (second messengers);
signal transduction via GTP-binding proteins
4. Precursor function
GTP
(mRNA
capping);
tetrahydrobiopterin,
(hydroxylation of aromatic amino acids)
5. Components of coenzymes
NAO, FAD, FMN, and coenzyme A
6. Activated intermediates
UDP-glucose (glycogen); CDP-choline (phospholipids);
SAM (methylation); PAPS (sulfacion)
7. Allosteric effectors
ATP (negative effector of PFK-I); AMP (positive
effector of phosphorylase b); dATP (negative effector
of ribonucleotide reductase).