
                                   chips 



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

   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. 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

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 of Pseudomona
s
RT   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 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(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   UniProtKB/Swiss-Prot; Q51417; AMIS_PSEAE.
XX


  [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 cause
s
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        6
0
     ctacctggcg agcctggagc acgagcgggt tcgcttcgta cggcgctgag cgacagtcac       12
0
     aggagaggaa acggatggga tcgcaccagg agcggccgct gatcggcctg ctgttctccg       18
0
     aaaccggcgt caccgccgat atcgagcgct cgcacgcgta tggcgcattg ctcgcggtcg       24
0
     agcaactgaa ccgcgagggc ggcgtcggcg gtcgcccgat cgaaacgctg tcccaggacc       30
0
     ccggcggcga cccggaccgc tatcggctgt gcgccgagga cttcattcgc aaccgggggg       36
0
     tacggttcct cgtgggctgc tacatgtcgc acacgcgcaa ggcggtgatg ccggtggtcg       42
0
     agcgcgccga cgcgctgctc tgctacccga ccccctacga gggcttcgag tattcgccga       48
0
     acatcgtcta cggcggtccg gcgccgaacc agaacagtgc gccgctggcg gcgtacctga       54
0
     ttcgccacta cggcgagcgg gtggtgttca tcggctcgga ctacatctat ccgcgggaaa       60
0
     gcaaccatgt gatgcgccac ctgtatcgcc agcacggcgg cacggtgctc gaggaaatct       66
0
     acattccgct gtatccctcc gacgacgact tgcagcgcgc cgtcgagcgc atctaccagg       72
0
     cgcgcgccga cgtggtcttc tccaccgtgg tgggcaccgg caccgccgag ctgtatcgcg       78
0
     ccatcgcccg tcgctacggc gacggcaggc ggccgccgat cgccagcctg accaccagcg       84
0
     aggcggaggt ggcgaagatg gagagtgacg tggcagaggg gcaggtggtg gtcgcgcctt       90
0
     acttctccag catcgatacg cccgccagcc gggccttcgt ccaggcctgc catggtttct       96
0
     tcccggagaa cgcgaccatc accgcctggg ccgaggcggc ctactggcag accttgttgc      102
0
     tcggccgcgc cgcgcaggcc gcaggcaact ggcgggtgga agacgtgcag cggcacctgt      108
0
     acgacatcga catcgacgcg ccacaggggc cggtccgggt ggagcgccag aacaaccaca      114
0
     gccgcctgtc ttcgcgcatc gcggaaatcg atgcgcgcgg cgtgttccag gtccgctggc      120
0
     agtcgcccga accgattcgc cccgaccctt atgtcgtcgt gcataacctc gacgactggt      126
0
     ccgccagcat gggcggggga ccgctcccat gagcgccaac tcgctgctcg gcagcctgcg      132
0
     cgagttgcag gtgctggtcc tcaacccgcc gggggaggtc agcgacgccc tggtcttgca      138
0
     gctgatccgc atcggttgtt cggtgcgcca gtgctggccg ccgccggaag ccttcgacgt      144
0
     gccggtggac gtggtcttca ccagcatttt ccagaatggc caccacgacg agatcgctgc      150
0
     gctgctcgcc gccgggactc cgcgcactac cctggtggcg ctggtggagt acgaaagccc      156
0
     cgcggtgctc tcgcagatca tcgagctgga gtgccacggc gtgatcaccc agccgctcga      162
0
     tgcccaccgg gtgctgcctg tgctggtatc ggcgcggcgc atcagcgagg aaatggcgaa      168
0
     gctgaagcag aagaccgagc agctccagga ccgcatcgcc ggccaggccc ggatcaacca      174
0
     ggccaaggtg ttgctgatgc agcgccatgg ctgggacgag cgcgaggcgc accagcacct      180
0
     gtcgcgggaa gcgatgaagc ggcgcgagcc gatcctgaag atcgctcagg agttgctggg      186
0
     aaacgagccg tccgcctgag cgatccgggc cgaccagaac aataacaaga ggggtatcgt      192
0
     catcatgctg ggactggttc tgctgtacgt tggcgcggtg ctgtttctca atgccgtctg      198
0
     gttgctgggc aagatcagcg gtcgggaggt ggcggtgatc aacttcctgg tcggcgtgct      204
0
     gagcgcctgc gtcgcgttct acctgatctt ttccgcagca gccgggcagg gctcgctgaa      210
0
     ggccggagcg ctgaccctgc tattcgcttt tacctatctg tgggtggccg ccaaccagtt      216
0
     cctcgag                                                                216
7
//

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 statictic plot for a nucleotide
   sequence

Author(s)

   Alan Bleasby (ajb © 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
