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| Code | Equivalence | Complement |
|---|---|---|
| A | A | T or U |
| C | C | G |
| G | G | C |
| T or U | T | A |
| M | A or C | K |
| R | A or G | Y |
| W | A or T | W |
| S | C or G | S |
| Y | C or T | R |
| K | G or T | M |
| V | A or C or G | B |
| H | A or C or T | D |
| D | A or G or T | H |
| B | C or G or T | V |
| X or N | A or C or G or T | X |
A nucleotide is a monomer or the structural unit of nucleotide chains forming nucleic acids as RNA and DNA. A nucleotide consists of a heterocyclic nucleobase, a pentose sugar, and a phosphate or polyphosphate group. Nucleotides also play important roles in cellular energy transport and transformations (notably ATP and NAD+/NADH), and in enzyme regulation (see for example, protein kinase).
The nucleobase can be a purines or pyrimidines, the sugar can be deoxyribose in DNA or ribose in RNA, and the phosphate chain can be a monophosphate, diphosphate, or triphosphate. A nucleotide that lacks the phosphate group is called nucleoside.
| Contents |
Nomenclature
Nucleotide names are abbreviated into standard four-letter codes. The first letter is lower case and indicates whether the nucleotide in question is a ribonucleotide (r) or deoxyribonucleotide (d). The second letter indicates the nucleobase:
- G: Guanine
- A: Adenine
- T: Thymine
- C: Cytosine
- U: Uracil not present in DNA, but takes the place of Thymine in RNA
The third and fourth letters indicate the length of the attached phosphate chain (Mono-, Di-, Tri-) and the presence of a phosphate (P).
For example, deoxy-cytosine-triphosphate is abbreviated as dCTP.
Chemical structures
Nucleotides
| Adenosine monophosphate AMP | Adenosine diphosphate ADP | Adenosine triphosphate ATP |
| Guanosine monophosphate GMP | Guanosine diphosphate GDP | Guanosine triphosphate GTP |
| Thymidine monophosphate TMP | Thymidine diphosphate TDP | Thymidine triphosphate TTP |
| Uridine monophosphate UMP | Uridine diphosphate UDP | Uridine triphosphate UTP |
| Cytidine monophosphate CMP | Cytidine diphosphate CDP | Cytidine triphosphate CTP |
Deoxynucleotides
| Deoxyadenosine monophosphate dAMP | Deoxyadenosine diphosphate dADP | Deoxyadenosine triphosphate dATP |
| Deoxyguanosine monophosphate dGMP | Deoxyguanosine diphosphate dGDP | Deoxyguanosine triphosphate dGTP |
| Deoxythymidine monophosphate dTMP | Deoxythymidine diphosphate dTDP | Deoxythymidine triphosphate dTTP |
| Deoxyuridine monophosphate dUMP | Deoxyuridine diphosphate dUDP | Deoxyuridine triphosphate dUTP |
| Deoxycytidine monophosphate dCMP | Deoxycytidine diphosphate dCDP | Deoxycytidine triphosphate dCTP |
See also
External links
- Abbreviations and Symbols for Nucleic Acids, Polynucleotides and their Constituents (IUPAC)
- Provisional Recommendations 2004 (IUPAC)
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