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chips |
This is a simple measure that quantifies how far the codon usage of a gene departs from equal usage of synonymous codons. This measure of synonymous codon usage bias, the 'effective number of codons used in a gene', Nc, can be easily calculated from codon usage data alone, and is independent of gene length and amino acid (aa) composition. Nc can take values from 20, in the case of extreme bias where one codon is exclusively used for each aa, to 61 when the use of alternative synonymous codons is equally likely. Nc thus provides an intuitively meaningful measure of the extent of codon preference in a gene.
The Nc statistic has problems in very short sequences (20 amino acids or less) which are yet to be fully resolved. They are caused by the need to consider amino acids which are missing in the sequence.
This calculation was originally in the EGCG package as "codfish" (codon usage for fission yeast). As Frank Wright is a vegan, we looked for a meat-free name for the EMBOSS version, "chips". The official explanation is "Codon Heterozygosity (Inverse of) in a Protein-coding Sequence"
If the sequence extends beyond the coding region then the start and/or end positions of the CDS must be provided because chips analyses exclusively protein coding regions.
% chips -sbeg 135 -send 1292 Codon usage statistics Input sequence(s): tembl:paamir Output file [paamir.chips]: |
Go to the input files for this example
Go to the output files for this example
Standard (Mandatory) qualifiers:
[-seqall] seqall Sequence database USA
[-outfile] outfile Output file name
Additional (Optional) qualifiers: (none)
Advanced (Unprompted) qualifiers:
-cfile codon Codon usage table name
-[no]sum boolean Sum codons over all sequences
Associated qualifiers:
"-seqall" associated qualifiers
-sbegin1 integer Start of each sequence to be used
-send1 integer End of each sequence to be used
-sreverse1 boolean Reverse (if DNA)
-sask1 boolean Ask for begin/end/reverse
-snucleotide1 boolean Sequence is nucleotide
-sprotein1 boolean Sequence is protein
-slower1 boolean Make lower case
-supper1 boolean Make upper case
-sformat1 string Input sequence format
-sdbname1 string Database name
-sid1 string Entryname
-ufo1 string UFO features
-fformat1 string Features format
-fopenfile1 string Features file name
"-outfile" associated qualifiers
-odirectory2 string Output directory
General qualifiers:
-auto boolean Turn off prompts
-stdout boolean Write standard output
-filter boolean Read standard input, write standard output
-options boolean Prompt for standard and additional values
-debug boolean Write debug output to program.dbg
-verbose boolean Report some/full command line options
-help boolean Report command line options. More
information on associated and general
qualifiers can be found with -help -verbose
-warning boolean Report warnings
-error boolean Report errors
-fatal boolean Report fatal errors
-die boolean Report deaths
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| Standard (Mandatory) qualifiers | Allowed values | Default | |
|---|---|---|---|
| [-seqall] (Parameter 1) |
Sequence database USA | Readable sequence(s) | Required |
| [-outfile] (Parameter 2) |
Output file name | Output file | <sequence>.chips |
| Additional (Optional) qualifiers | Allowed values | Default | |
| (none) | |||
| Advanced (Unprompted) qualifiers | Allowed values | Default | |
| -cfile | Codon usage table name | Codon usage file in EMBOSS data path | Ehum.cut |
| -[no]sum | Sum codons over all sequences | Boolean value Yes/No | Yes |
ID PAAMIR standard; DNA; PRO; 2167 BP.
XX
AC X13776; M43175;
XX
SV X13776.1
XX
DT 19-APR-1989 (Rel. 19, Created)
DT 17-FEB-1997 (Rel. 50, Last updated, Version 22)
XX
DE Pseudomonas aeruginosa amiC and amiR gene for aliphatic amidase regulation
XX
KW aliphatic amidase regulator; amiC gene; amiR gene.
XX
OS Pseudomonas aeruginosa
OC Bacteria; Proteobacteria; gamma subdivision; Pseudomonadaceae; Pseudomonas.
XX
RN [1]
RP 1167-2167
RA Rice P.M.;
RT ;
RL Submitted (16-DEC-1988) to the EMBL/GenBank/DDBJ databases.
RL Rice P.M., EMBL, Postfach 10-2209, Meyerhofstrasse 1, 6900 Heidelberg, FRG.
XX
RN [2]
RP 1167-2167
RX MEDLINE; 89211409.
RA Lowe N., Rice P.M., Drew R.E.;
RT "Nucleotide sequence of the aliphatic amidase regulator gene of Pseudomonas
RT aeruginosa";
RL FEBS Lett. 246:39-43(1989).
XX
RN [3]
RP 1-1292
RX MEDLINE; 91317707.
RA Wilson S., Drew R.;
RT "Cloning and DNA seqence of amiC, a new gene regulating expression of the
RT Pseudomonas aeruginosa aliphatic amidase, and purification of the amiC
RT product.";
RL J. Bacteriol. 173:4914-4921(1991).
XX
RN [4]
RP 1-2167
RA Rice P.M.;
RT ;
RL Submitted (04-SEP-1991) to the EMBL/GenBank/DDBJ databases.
RL Rice P.M., EMBL, Postfach 10-2209, Meyerhofstrasse 1, 6900 Heidelberg, FRG.
XX
DR SWISS-PROT; P10932; AMIR_PSEAE.
DR SWISS-PROT; P27017; AMIC_PSEAE.
DR SWISS-PROT; Q51417; AMIS_PSEAE.
[Part of this file has been deleted for brevity]
FT phenotype"
FT /replace=""
FT /gene="amiC"
FT misc_feature 1
FT /note="last base of an XhoI site"
FT misc_feature 648..653
FT /note="end of 658bp XhoI fragment, deletion in pSW3 causes
FT constitutive expression of amiE"
FT conflict 1281
FT /replace="g"
FT /citation=[3]
XX
SQ Sequence 2167 BP; 363 A; 712 C; 730 G; 362 T; 0 other;
ggtaccgctg gccgagcatc tgctcgatca ccaccagccg ggcgacggga actgcacgat 60
ctacctggcg agcctggagc acgagcgggt tcgcttcgta cggcgctgag cgacagtcac 120
aggagaggaa acggatggga tcgcaccagg agcggccgct gatcggcctg ctgttctccg 180
aaaccggcgt caccgccgat atcgagcgct cgcacgcgta tggcgcattg ctcgcggtcg 240
agcaactgaa ccgcgagggc ggcgtcggcg gtcgcccgat cgaaacgctg tcccaggacc 300
ccggcggcga cccggaccgc tatcggctgt gcgccgagga cttcattcgc aaccgggggg 360
tacggttcct cgtgggctgc tacatgtcgc acacgcgcaa ggcggtgatg ccggtggtcg 420
agcgcgccga cgcgctgctc tgctacccga ccccctacga gggcttcgag tattcgccga 480
acatcgtcta cggcggtccg gcgccgaacc agaacagtgc gccgctggcg gcgtacctga 540
ttcgccacta cggcgagcgg gtggtgttca tcggctcgga ctacatctat ccgcgggaaa 600
gcaaccatgt gatgcgccac ctgtatcgcc agcacggcgg cacggtgctc gaggaaatct 660
acattccgct gtatccctcc gacgacgact tgcagcgcgc cgtcgagcgc atctaccagg 720
cgcgcgccga cgtggtcttc tccaccgtgg tgggcaccgg caccgccgag ctgtatcgcg 780
ccatcgcccg tcgctacggc gacggcaggc ggccgccgat cgccagcctg accaccagcg 840
aggcggaggt ggcgaagatg gagagtgacg tggcagaggg gcaggtggtg gtcgcgcctt 900
acttctccag catcgatacg cccgccagcc gggccttcgt ccaggcctgc catggtttct 960
tcccggagaa cgcgaccatc accgcctggg ccgaggcggc ctactggcag accttgttgc 1020
tcggccgcgc cgcgcaggcc gcaggcaact ggcgggtgga agacgtgcag cggcacctgt 1080
acgacatcga catcgacgcg ccacaggggc cggtccgggt ggagcgccag aacaaccaca 1140
gccgcctgtc ttcgcgcatc gcggaaatcg atgcgcgcgg cgtgttccag gtccgctggc 1200
agtcgcccga accgattcgc cccgaccctt atgtcgtcgt gcataacctc gacgactggt 1260
ccgccagcat gggcggggga ccgctcccat gagcgccaac tcgctgctcg gcagcctgcg 1320
cgagttgcag gtgctggtcc tcaacccgcc gggggaggtc agcgacgccc tggtcttgca 1380
gctgatccgc atcggttgtt cggtgcgcca gtgctggccg ccgccggaag ccttcgacgt 1440
gccggtggac gtggtcttca ccagcatttt ccagaatggc caccacgacg agatcgctgc 1500
gctgctcgcc gccgggactc cgcgcactac cctggtggcg ctggtggagt acgaaagccc 1560
cgcggtgctc tcgcagatca tcgagctgga gtgccacggc gtgatcaccc agccgctcga 1620
tgcccaccgg gtgctgcctg tgctggtatc ggcgcggcgc atcagcgagg aaatggcgaa 1680
gctgaagcag aagaccgagc agctccagga ccgcatcgcc ggccaggccc ggatcaacca 1740
ggccaaggtg ttgctgatgc agcgccatgg ctgggacgag cgcgaggcgc accagcacct 1800
gtcgcgggaa gcgatgaagc ggcgcgagcc gatcctgaag atcgctcagg agttgctggg 1860
aaacgagccg tccgcctgag cgatccgggc cgaccagaac aataacaaga ggggtatcgt 1920
catcatgctg ggactggttc tgctgtacgt tggcgcggtg ctgtttctca atgccgtctg 1980
gttgctgggc aagatcagcg gtcgggaggt ggcggtgatc aacttcctgg tcggcgtgct 2040
gagcgcctgc gtcgcgttct acctgatctt ttccgcagca gccgggcagg gctcgctgaa 2100
ggccggagcg ctgaccctgc tattcgcttt tacctatctg tgggtggccg ccaaccagtt 2160
cctcgag 2167
//
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# CHIPS codon usage statistics Nc = 32.951 |
If all codons are used, the Nc value will be 61. If only one codon is used for each amino acid the Nc value will be 20. Low values therefore indicate a strong codon bias, and high values indicate a low bias (and possibly a non-coding region).
The codon usage table is by default the file "CODONS/Ehum.cut" in the EMBOSS distribution directory.
EMBOSS data files are distributed with the application and stored in the standard EMBOSS data directory, which is defined by EMBOSS environment variable EMBOSS_DATA.
Users can provide their own data files in their own directories. Project specific files can be put in the current directory, or for tidier directory listings in a subdirectory called ".embossdata". Files for all EMBOSS runs can be put in the user's home directory, or again in a subdirectory called ".embossdata".
The directories are searched in the following order:
| Program name | Description |
|---|---|
| cai | CAI codon adaptation index |
| codcmp | Codon usage table comparison |
| cusp | Create a codon usage table |
| syco | Synonymous codon usage Gribskov statistic plot |