Nucleotide

Nucleotide codes

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

1 Nomenclature 2 Chemical structures 2.1 Nucleotides 2.2 Deoxynucleotides 3 See also 4 External links

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

• Gene
• Genetics
• Chromosome

External links

• Abbreviations and Symbols for Nucleic Acids, Polynucleotides and their Constituents (IUPAC)
• Provisional Recommendations 2004 (IUPAC)