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.
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
Last updated: 06-01-2005 22:47:57
Last updated: 08-16-2005 17:50:30