Nucleoside triphosphate

In biochemistry and molecular biology, a nucleoside triphosphate (NTP) is a molecule containing a nucleoside bound to three phosphate groups. It is thus one type of nucleotide. Nucleoside triphosphates are necessary for life, as they provide the building blocks of nucleic acids (DNA and RNA) and have many other roles in cell metabolism and regulation. NTPs generally provide energy and phosphate groups for phosphorylation.

Naturally-occurring nucleoside triphosphates include adenosine triphosphate (ATP, a major source of cellular energy), guanosine triphosphate (GTP, a frequent cofactor of enzymes and proteins), cytidine triphosphate (CTP), 5-methyluridine triphosphate (m⁵UTP), and uridine triphosphate (UTP).

The terms ATP, GTP, CTP, and UTP refer to those nucleoside triphosphates that contain ribose. The nucleoside triphosphates containing deoxyribose are called dNTPs, and take the prefix deoxy- in their names and small d- in their abbreviations: deoxyadenosine triphosphate (dATP), deoxyguanosine triphosphate (dGTP), deoxycytidine triphosphate (dCTP), deoxythymidine triphosphate (dTTP) and deoxyuridine triphosphate (dUTP). The dNTPs are the building blocks for DNA replication (they lose two of the phosphate groups in the process of incorporation).