                                    chips



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Function

   Calculates Nc codon usage statistic

Description

   chips calculates Frank Wright's Nc statistic for a nucleotide sequence.
   This is the "effective number of codons used in a gene sequence" (ref
   1), and is a simple measure of synonymous codon usage bias. Nc
   quantifies how far the codon usage of a gene departs from equal usage
   of synonymous codons.

   Nc is easily calculated from codon usage data alone and is independent
   of gene length and amino acid composition. Nc can take values from 20,
   in the case of extreme bias where one codon is exclusively used for
   each amino acid, 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. Low values therefore indicate
   a strong codon bias, and high values indicate a low bias (and possibly
   a non-coding region).

Usage

   Here is a sample session with chips


% chips -sbeg 135 -send 1292
Calculates Nc codon usage statistic
Input nucleotide sequence(s): tembl:x13776
Output file [x13776.chips]:


   Go to the input files for this example
   Go to the output files for this example

Command line arguments

Calculates Nc codon usage statistic
Version: EMBOSS:6.2.0

   Standard (Mandatory) qualifiers:
  [-seqall]            seqall     Nucleotide sequence(s) filename and optional
                                  format, or reference (input USA)
  [-outfile]           outfile    [*.chips] Output file name

   Additional (Optional) qualifiers: (none)
   Advanced (Unprompted) qualifiers:
   -[no]sum            boolean    [Y] 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 first file to standard output
   -filter             boolean    Read first file from standard input, write
                                  first file to 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 and exit. 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 dying program messages
   -version            boolean    Report version number and exit


Input file format

   A nucleic acid sequence USA.

  Input files for usage example

   'tembl:x13776' is a sequence entry in the example nucleic acid database
   'tembl'

  Database entry: tembl:x13776

ID   X13776; SV 1; linear; genomic DNA; STD; PRO; 2167 BP.
XX
AC   X13776; M43175;
XX
DT   19-APR-1989 (Rel. 19, Created)
DT   14-NOV-2006 (Rel. 89, Last updated, Version 24)
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; Gammaproteobacteria; Pseudomonadales;
OC   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   DOI; 10.1016/0014-5793(89)80249-2.
RX   PUBMED; 2495988.
RA   Lowe N., Rice P.M., Drew R.E.;
RT   "Nucleotide sequence of the aliphatic amidase regulator gene (amiR) of
RT   Pseudomonas aeruginosa";
RL   FEBS Lett. 246(1-2):39-43(1989).
XX
RN   [3]
RP   1-1292
RX   PUBMED; 1907262.
RA   Wilson S., Drew R.;
RT   "Cloning and DNA sequence 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(16):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   GOA; Q51417.
DR   InterPro; IPR003211; AmiSUreI_transpt.
DR   UniProtKB/Swiss-Prot; Q51417; AMIS_PSEAE.


  [Part of this file has been deleted for brevity]

FT                   /replace=""
FT                   /note="ClaI fragment deleted in pSW36,  constitutive
FT                   phenotype"
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
//

Output file format

   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).

  Output files for usage example

  File: x13776.chips

# CHIPS codon usage statistics

Nc = 32.951

Data files

   chips reads the codon usage file "CODONS/Ehum.cut" from the EMBOSS data
   directory. It uses the file as a template only and ignores the date
   itself.

   EMBOSS data files are distributed with the application and stored in
   the standard EMBOSS data directory, which is defined by the EMBOSS
   environment variable EMBOSS_DATA.

   To see the available EMBOSS data files, run:

% embossdata -showall

   To fetch one of the data files (for example 'Exxx.dat') into your
   current directory for you to inspect or modify, run:

% embossdata -fetch -file Exxx.dat


   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:
     * . (your current directory)
     * .embossdata (under your current directory)
     * ~/ (your home directory)
     * ~/.embossdata

Notes

   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".

References

    1. Wright, F. (1990) Gene 87:23-29 "The 'effective number of codons'
       used in a gene."

Warnings

   The Nc statistic has problems for 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.

   chips analyses exclusively protein coding regions. If the provided
   sequence extends beyond the coding region then the start and/or end
   positions of the CDS must be specified by using the -sbegin and -send
   qualifiers that are in-built for all sequence types.

Diagnostic Error Messages

   None.

Exit status

   It always exits with a status of 0.

Known bugs

   None.

See also

   Program name     Description
   cai              Calculate codon adaptation index
   codcmp           Codon usage table comparison
   cusp             Create a codon usage table from nucleotide sequence(s)
   syco             Draw synonymous codon usage statistic plot for a nucleotide
                    sequence

Author(s)

   Alan Bleasby (ajb (c) ebi.ac.uk)
   European Bioinformatics Institute, Wellcome Trust Genome Campus,
   Hinxton, Cambridge CB10 1SD, UK

History

   1999 - Written - Alan Bleasby.

Target users

   This program is intended to be used by everyone and everything, from
   naive users to embedded scripts.

Comments

   None
