CodonTableCodonTable

E. coli Codon Usage Table (Escherichia coli)

See the most used codons, highest-fraction synonymous codons, and full codon usage frequencies for Escherichia coli.

Use frequency to find the most common codons in this organism, and use fraction to compare synonymous codon preference within the same amino acid family.

Choose Organism and Display

These settings control the summary cards and the full codon usage table below.

Top Codons by Frequency

Codons ranked by frequency per 1,000 codons in the selected organism.
CTG
Amino acid: L
Fraction 0.47
Freq 48.4
GAA
Amino acid: E
Fraction 0.68
Freq 39.1
AAA
Amino acid: K
Fraction 0.74
Freq 35.3
GAT
Amino acid: D
Fraction 0.63
Freq 32.7
GCG
Amino acid: A
Fraction 0.33
Freq 30.1
ATT
Amino acid: I
Fraction 0.49
Freq 29.8
CAG
Amino acid: Q
Fraction 0.66
Freq 28.4
GGC
Amino acid: G
Fraction 0.37
Freq 27.1

Top Codons by Fraction

Synonymous codons ranked by fraction. Stop codons and single-codon amino acids are excluded.
AAA
Amino acid: K
Fraction 0.74
Freq 35.3
GAA
Amino acid: E
Fraction 0.68
Freq 39.1
CAG
Amino acid: Q
Fraction 0.66
Freq 28.4
GAT
Amino acid: D
Fraction 0.63
Freq 32.7
TAT
Amino acid: Y
Fraction 0.59
Freq 17.5
TTT
Amino acid: F
Fraction 0.58
Freq 22.1
CAT
Amino acid: H
Fraction 0.57
Freq 12.5
TGC
Amino acid: C
Fraction 0.54
Freq 6.1

Preferred Codons by Amino Acid

One preferred codon per amino acid, ranked by frequency to surface practical defaults.
CTG
Amino acid: L
Fraction 0.47
Freq 48.4
GAA
Amino acid: E
Fraction 0.68
Freq 39.1
AAA
Amino acid: K
Fraction 0.74
Freq 35.3
GAT
Amino acid: D
Fraction 0.63
Freq 32.7
GCG
Amino acid: A
Fraction 0.33
Freq 30.1
ATT
Amino acid: I
Fraction 0.49
Freq 29.8
CAG
Amino acid: Q
Fraction 0.66
Freq 28.4
GGC
Amino acid: G
Fraction 0.37
Freq 27.1

Escherichia coli (E.coli): (Genetic code: Standard)

Print-friendly 2-column table in genetic code order. Frequency is shown per 1,000 codons.
TripletAmino acidFractionFrequency/ThousandNumberTripletAmino acidFractionFrequency/ThousandNumber
TTT
TTC
TTA
TTG
F
F
L
L
0.58
0.42
0.14
0.13
22.1
16.0
14.3
13.0
80,995
58,774
52,382
47,500
TCT
TCC
TCA
TCG
S
S
S
S
0.17
0.15
0.14
0.14
10.4
9.1
8.9
8.5
38,027
33,430
32,715
31,146
TAT
TAC
TAA
TAG
Y
Y
*
*
0.59
0.41
0.61
0.09
17.5
12.2
2.0
0.3
63,937
44,631
7,356
989
TGT
TGC
TGA
TGG
C
C
*
W
0.46
0.54
0.30
1.00
5.2
6.1
1.0
13.9
19,138
22,188
3,623
50,991
CTT
CTC
CTA
CTG
L
L
L
L
0.12
0.10
0.04
0.47
11.9
10.2
4.2
48.4
43,449
37,347
15,409
177,210
CCT
CCC
CCA
CCG
P
P
P
P
0.18
0.13
0.20
0.49
7.5
5.4
8.6
20.9
27,340
19,666
31,534
76,644
CAT
CAC
CAA
CAG
H
H
Q
Q
0.57
0.43
0.34
0.66
12.5
9.3
14.6
28.4
45,879
34,078
53,394
104,171
CGT
CGC
CGA
CGG
R
R
R
R
0.36
0.36
0.07
0.11
20.0
19.7
3.8
5.9
73,197
72,212
13,844
21,552
ATT
ATC
ATA
ATG
I
I
I
M
0.49
0.39
0.11
1.00
29.8
23.7
6.8
26.4
109,072
86,796
24,984
96,695
ACT
ACC
ACA
ACG
T
T
T
T
0.19
0.40
0.17
0.25
10.3
22.0
9.3
13.7
37,842
80,547
33,910
50,269
AAT
AAC
AAA
AAG
N
N
K
K
0.49
0.51
0.74
0.26
20.6
21.4
35.3
12.4
75,436
78,443
129,137
45,459
AGT
AGC
AGA
AGG
S
S
R
R
0.16
0.25
0.07
0.04
9.9
15.2
3.6
2.1
36,097
55,551
13,152
7,607
GTT
GTC
GTA
GTG
V
V
V
V
0.28
0.20
0.17
0.35
19.8
14.3
11.6
24.4
72,584
52,439
42,420
89,265
GCT
GCC
GCA
GCG
A
A
A
A
0.18
0.26
0.23
0.33
17.1
24.2
21.2
30.1
62,479
88,721
77,547
110,308
GAT
GAC
GAA
GAG
D
D
E
E
0.63
0.37
0.68
0.32
32.7
19.2
39.1
18.7
119,939
70,394
143,353
68,609
GGT
GGC
GGA
GGG
G
G
G
G
0.35
0.37
0.13
0.15
25.5
27.1
9.5
11.3
93,325
99,390
34,799
41,277
Showing 64 entries for Escherichia coli (E.coli).
Frequency is measured per 1,000 codons. Fraction compares codons that encode the same amino acid.

Common Searches

E. coli codon usage table
E. coli codon usage highest fraction
E. coli preferred codons
Escherichia coli codon bias

How To Use This Page

Use the summary cards to find the most used and highest-fraction codons quickly.
Switch sorting in the full table when you want to compare by frequency, fraction, or count.
Use the full organism list and search codons/amino acids on the Codon Usage Frequency Table.

FAQ

What are the most used codons in Escherichia coli?

Use the "Most Used Codons" section to see which codons appear most often in Escherichia coli. The ranking is based on frequency per 1,000 codons.

Which codons have the highest fraction in Escherichia coli?

Use the "Highest Fraction Codons" section to compare synonymous codons for the same amino acid. Single-codon amino acids and stop codons are excluded so the ranking reflects codon preference rather than trivial 1.00 values.

What is the difference between codon frequency and codon fraction in Escherichia coli?

Frequency measures how often a codon appears per 1,000 codons in the dataset. Fraction measures how strongly that codon is preferred relative to alternative codons encoding the same amino acid.

How should I use this Escherichia coli codon usage table for optimization?

Start with the preferred-codon summaries to identify likely defaults, then review the full table below before making codon optimization or expression design decisions.