52.3%GC3 content

55.6Effective codons (Nc)

247Coding sequences

19/26GC3 rank here

Scope: nuclear genes only

NCBI table 1 (Standard). Do not apply these frequencies to mitochondrial genes, where AGA, AGG, ATA and TGA carry different meanings. The four reassignments.

What distinguishes this table

The most constrained choice in Giant panda is glutamine: of its 2 synonymous codons, CAG takes 72% of the family. Tyrosine sits at the other end, spread almost evenly across its options (evenness 1.00 against 0.85 for glutamine). Those two families are where a codon-optimizer has the most and the least room to move.

Measured across all 59 sense codons, this table correlates most closely with Cattle (r = 0.996) and least with M. tuberculosis (r = 0.714). A sequence tuned for the first would need little adjustment to move here; one tuned for the second would need a great deal.

Relative to the average across the 26 organisms on this site, Giant panda leans hardest on TAT (+0.062 against the mean) and avoids ATC most (-0.062). Those two are the codons that most distinguish this table from the others.

Preferred and avoided codons

Amino acid	Preferred	Freq	RSCU	Avoided	Freq	RSCU
Alanine A	GCC	0.370	1.48	GCG	0.094	0.38
Arginine R	AGA	0.231	1.38	CGA	0.108	0.65
Asparagine N	AAT	0.518	1.04	AAC	0.482	0.96
Aspartate D	GAT	0.514	1.03	GAC	0.486	0.97
Cysteine C	TGC	0.530	1.06	TGT	0.470	0.94
Glutamate E	GAG	0.517	1.03	GAA	0.483	0.97
Glutamine Q	CAG	0.725	1.45	CAA	0.275	0.55
Glycine G	GGC	0.298	1.19	GGT	0.206	0.83
Histidine H	CAC	0.553	1.11	CAT	0.447	0.89
Isoleucine I	ATC	0.415	1.24	ATA	0.179	0.54
Leucine L	CTG	0.342	2.05	CTA	0.071	0.42
Lysine K	AAG	0.531	1.06	AAA	0.469	0.94
Phenylalanine F	TTC	0.521	1.04	TTT	0.479	0.96
Proline P	CCT	0.322	1.29	CCG	0.101	0.41
Serine S	AGC	0.231	1.39	TCG	0.053	0.32
Threonine T	ACC	0.317	1.27	ACG	0.110	0.44
Tyrosine Y	TAT	0.506	1.01	TAC	0.494	0.99
Valine V	GTG	0.444	1.78	GTA	0.131	0.52

Full codon usage table

Amino acid	Codon	Frequency	RSCU
Alanine A	GCC	0.3705	1.482
	GCT	0.3013	1.205
	GCA	0.2339	0.936
	GCG	0.0943	0.377
Arginine R	AGA	0.2306	1.384
	AGG	0.1929	1.157
	CGG	0.1834	1.100
	CGC	0.1666	1.000
	CGT	0.1181	0.709
	CGA	0.1085	0.651
Asparagine N	AAT	0.5180	1.036
Asparagine N	AAC	0.4820	0.964
Aspartate D	GAT	0.5137	1.027
Aspartate D	GAC	0.4863	0.973
Cysteine C	TGC	0.5299	1.060
Cysteine C	TGT	0.4701	0.940
Glutamate E	GAG	0.5168	1.034
Glutamate E	GAA	0.4832	0.966
Glutamine Q	CAG	0.7250	1.450
Glutamine Q	CAA	0.2750	0.550
Glycine G	GGC	0.2979	1.192
	GGA	0.2851	1.140
	GGG	0.2107	0.843
	GGT	0.2063	0.825
Histidine H	CAC	0.5531	1.106
Histidine H	CAT	0.4469	0.894
Isoleucine I	ATC	0.4149	1.245
	ATT	0.4055	1.216
	ATA	0.1795	0.538
Leucine L	CTG	0.3424	2.054
	CTC	0.1808	1.085
	CTT	0.1578	0.947
	TTG	0.1559	0.935
	TTA	0.0923	0.554
	CTA	0.0708	0.425
Lysine K	AAG	0.5306	1.061
Lysine K	AAA	0.4694	0.939
Methionine M	ATG	1.0000	1.000
Phenylalanine F	TTC	0.5207	1.041
Phenylalanine F	TTT	0.4793	0.959
Proline P	CCT	0.3217	1.287
	CCA	0.3047	1.219
	CCC	0.2721	1.088
	CCG	0.1014	0.406
Serine S	AGC	0.2312	1.387
	TCC	0.2125	1.275
	TCT	0.1964	1.178
	AGT	0.1551	0.931
	TCA	0.1523	0.914
	TCG	0.0526	0.316
Threonine T	ACC	0.3165	1.266
	ACT	0.2945	1.178
	ACA	0.2790	1.116
	ACG	0.1101	0.440
Tryptophan W	TGG	1.0000	1.000
Tyrosine Y	TAT	0.5059	1.012
Tyrosine Y	TAC	0.4941	0.988
Valine V	GTG	0.4441	1.776
	GTC	0.2180	0.872
	GTT	0.2071	0.828
	GTA	0.1308	0.523

Provenance

Computed from 247 RefSeq coding sequences for Ailuropoda melanoleuca, sampled and counted codon by codon. Frequencies are relative within each amino acid family. Page generated 2026-08-09.

The full derivation of GC3, RSCU and the effective number of codons, along with the limits of each, is set out once in the methods note rather than repeated on every page.

Use this table

Nucleora codon-optimizes a coding sequence against this table directly, then folds the result and reports where structure would interfere with expression.

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