Nucleoside triphosphate
Encyclopedia
Nucleoside triphosphate (NTP) is a nucleoside
with three phosphate
s. Natural nucleoside triphosphates include adenosine triphosphate
(ATP), guanosine triphosphate
(GTP), cytidine triphosphate
(CTP), 5-methyluridine triphosphate (m5UTP), and uridine triphosphate (UTP). These terms refer to those nucleoside triphosphates that contain ribose. The nucleoside triphosphates containing deoxyribose take prefix deoxy- in their names (except for the thymidine
derivative) and small d- in their abbreviations: deoxyadenosine triphosphate
(dATP), deoxyguanosine triphosphate
(dGTP), deoxycytidine triphosphate
(dCTP), thymidine triphosphate
(dTTP) and deoxyuridine triphosphate. Check the entry nucleoside
for table and description of these compounds.
Apart from (d)ATP, (d)GTP, (d)CTP, (d)TTP and (d)UTP, there are other less abundant NTPs, such as intermediates of nucleotide metabolism, but also "rare" natural nucleotides or even artificial nucleotides. The rare NTP are tautomeric forms of the NTPs. They cause mismatched base pairing during DNA replication. For example, a tautomeric form of cytosine is capable of forming 3 h-bonds with adenine, and it will spontaneously revert to its original cytosine form, causing a mismatch. By a similar token, the deamination of cytosine leads to uracil, whereas a deamination of a commonly encountered (in eukaryotes) 5-methylcytosine will lead to thymine. However, the 5' to 3' DNA replication ensures that these mismatched bases are excised.
Nucleotide
derivatives are of unparalleled importance for current natural life forms, as they are building blocks of nucleic acid
s and have thousands of other roles in cell metabolism and regulation. ATP is a major source of cellular energy. GTP is a very frequent cofactor of enzymes and proteins. NTPs generally provide energy and phosphate group for phosphorylations.
Generally nucleoside
s are nucleotide
s (e.g. adenine, guanine, cytosine...) that lack phosphates. However, for the sake of technical terminology
, nucleotides are given classifications as nucleosides with a suffix describing the number of phosphates present in a specific unit. For example, if a nucleotide has one phosphate, it is a nucleoside monophosphate (NMP). If the nucleotide has two phosphates, then it is called a nucleoside diphosphate (NDP), and for three, it is a nucleoside triphosphate (NTP). The nucleotides that contain a ribose
sugar are the monomers of RNA
and those that contain a deoxyribose
sugar compose DNA
.
NTPs, NDPs and NMPs are ubiquitous in cell cytoplasm, nucleus and organelles. Given their multifarious functions, their levels are under fairly tight metabolic control. Most of the discussion on mutual ratios of nucleotides should belong under entry nucleotide
, but concentrating strictly on the abundance of the triphosphorylated versions, we find that ATP spending is replenished by oxidative phosphorylation
, while phosphorylation status of other nucleotides is regulated by NDP kinase
s (EC 2.7.4.6) and NMP kinase
s (EC 2.7.4.4) that use ATP pool as their cross-phosphorylation source.
Nucleoside
Nucleosides are glycosylamines consisting of a nucleobase bound to a ribose or deoxyribose sugar via a beta-glycosidic linkage...
with three phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
s. Natural nucleoside triphosphates include adenosine triphosphate
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
(ATP), guanosine triphosphate
Guanosine triphosphate
Guanosine-5'-triphosphate is a purine nucleoside triphosphate. It can act as a substrate for the synthesis of RNA during the transcription process...
(GTP), cytidine triphosphate
Cytidine triphosphate
Cytidine triphosphate is a pyrimidine nucleoside triphosphate.CTP is a substrate in the synthesis of RNA.CTP is a high-energy molecule equal to ATP, but its role in the organism is more specific than that of ATP....
(CTP), 5-methyluridine triphosphate (m5UTP), and uridine triphosphate (UTP). These terms refer to those nucleoside triphosphates that contain ribose. The nucleoside triphosphates containing deoxyribose take prefix deoxy- in their names (except for the thymidine
Thymidine
Thymidine is a chemical compound, more precisely a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine in double-stranded DNA...
derivative) and small d- in their abbreviations: deoxyadenosine triphosphate
Deoxyadenosine triphosphate
Deoxyadenosine triphosphate is a nucleoside triphosphate used in cells for DNA synthesis.-External links:KEGG entry on...
(dATP), deoxyguanosine triphosphate
Deoxyguanosine triphosphate
Deoxyguanosine triphosphate is a nucleoside triphosphate, and a nucleotide precursor used in cells for DNA synthesis. The substance is used in the polymerase chain reaction technique, in sequencing, and in cloning. It is also the competitor of inhibition onset by acyclovir in the treatment of HSV...
(dGTP), deoxycytidine triphosphate
Deoxycytidine triphosphate
Deoxycytidine triphosphate is a nucleoside triphosphate that is used whenever DNA is synthesized, such as in the polymerase chain reaction.e.g.:A chemical equation can be written that represents the process:...
(dCTP), thymidine triphosphate
Thymidine triphosphate
5-Methyluridine triphosphate or m5UTP is one of five nucleoside triphosphates. It is the ribonucleoside triphosphate of thymidine, but the 5-methyluridine nomenclature is used because the term thymidine triphosphate is used for the deoxyribonucleoside by convention.-References:...
(dTTP) and deoxyuridine triphosphate. Check the entry nucleoside
Nucleoside
Nucleosides are glycosylamines consisting of a nucleobase bound to a ribose or deoxyribose sugar via a beta-glycosidic linkage...
for table and description of these compounds.
Apart from (d)ATP, (d)GTP, (d)CTP, (d)TTP and (d)UTP, there are other less abundant NTPs, such as intermediates of nucleotide metabolism, but also "rare" natural nucleotides or even artificial nucleotides. The rare NTP are tautomeric forms of the NTPs. They cause mismatched base pairing during DNA replication. For example, a tautomeric form of cytosine is capable of forming 3 h-bonds with adenine, and it will spontaneously revert to its original cytosine form, causing a mismatch. By a similar token, the deamination of cytosine leads to uracil, whereas a deamination of a commonly encountered (in eukaryotes) 5-methylcytosine will lead to thymine. However, the 5' to 3' DNA replication ensures that these mismatched bases are excised.
Nucleotide
Nucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
derivatives are of unparalleled importance for current natural life forms, as they are building blocks of nucleic acid
Nucleic acid
Nucleic acids are biological molecules essential for life, and include DNA and RNA . Together with proteins, nucleic acids make up the most important macromolecules; each is found in abundance in all living things, where they function in encoding, transmitting and expressing genetic information...
s and have thousands of other roles in cell metabolism and regulation. ATP is a major source of cellular energy. GTP is a very frequent cofactor of enzymes and proteins. NTPs generally provide energy and phosphate group for phosphorylations.
Generally nucleoside
Nucleoside
Nucleosides are glycosylamines consisting of a nucleobase bound to a ribose or deoxyribose sugar via a beta-glycosidic linkage...
s are nucleotide
Nucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
s (e.g. adenine, guanine, cytosine...) that lack phosphates. However, for the sake of technical terminology
Technical terminology
Technical terminology is the specialized vocabulary of any field, not just technical fields. The same is true of the synonyms technical terms, terms of art, shop talk and words of art, which do not necessarily refer to technology or art...
, nucleotides are given classifications as nucleosides with a suffix describing the number of phosphates present in a specific unit. For example, if a nucleotide has one phosphate, it is a nucleoside monophosphate (NMP). If the nucleotide has two phosphates, then it is called a nucleoside diphosphate (NDP), and for three, it is a nucleoside triphosphate (NTP). The nucleotides that contain a ribose
Ribose
Ribose is an organic compound with the formula C5H10O5; specifically, a monosaccharide with linear form H––4–H, which has all the hydroxyl groups on the same side in the Fischer projection....
sugar are the monomers of RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
and those that contain a deoxyribose
Deoxyribose
Deoxyribose, more, precisely 2-deoxyribose, is a monosaccharide with idealized formula H---3-H. Its name indicates that it is a deoxy sugar, meaning that it is derived from the sugar ribose by loss of an oxygen atom...
sugar compose DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
.
NTPs, NDPs and NMPs are ubiquitous in cell cytoplasm, nucleus and organelles. Given their multifarious functions, their levels are under fairly tight metabolic control. Most of the discussion on mutual ratios of nucleotides should belong under entry nucleotide
Nucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
, but concentrating strictly on the abundance of the triphosphorylated versions, we find that ATP spending is replenished by oxidative phosphorylation
Oxidative phosphorylation
Oxidative phosphorylation is a metabolic pathway that uses energy released by the oxidation of nutrients to produce adenosine triphosphate . Although the many forms of life on earth use a range of different nutrients, almost all aerobic organisms carry out oxidative phosphorylation to produce ATP,...
, while phosphorylation status of other nucleotides is regulated by NDP kinase
Nucleoside-diphosphate kinase
Nucleoside-diphosphate kinases are enzymes that catalyze the exchange of phosphate groups between different nucleoside diphosphates...
s (EC 2.7.4.6) and NMP kinase
Nucleoside-phosphate kinase
In enzymology, a nucleoside-phosphate kinase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are ATP and nucleoside phosphate, whereas its two products are ADP and nucleoside diphosphate....
s (EC 2.7.4.4) that use ATP pool as their cross-phosphorylation source.