| charge

## Function

Protein charge plot

## Description

charge reads a protein sequence and writes a file (or plots a graph) of the charges of the amino acids within a window of specified length as the window is moved along the sequence.

## Algorithm

charge uses the column "charge" from the datafile Eamino.dat. It gives the residues 'D' and 'E' a charge of -1, 'K' and 'R' a charge of +1, and the residue 'H' a charge of +0.5. Then it calculates the mean charge across -window (default is 5).

## Usage

Here is a sample session with charge

    % charge tsw:hbb_human
    Protein charge plot
    Output file [hbb_human.charge]:

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

## Command line arguments

       Standard (Mandatory) qualifiers (* if not always prompted):
      [-seqall]            seqall     Sequence database USA
    *  -graph              xygraph    Graph type
    *  -outfile            outfile    Output file name

       Additional (Optional) qualifiers:
       -window             integer    Window

       Advanced (Unprompted) qualifiers:
       -aadata             datafile   Amino acid property data file name
       -plot               toggle     Produce graphic

       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

       "-graph" associated qualifiers
       -gprompt             boolean    Graph prompting
       -gtitle              string     Graph title
       -gsubtitle           string     Graph subtitle
       -gxtitle             string     Graph x axis title
       -gytitle             string     Graph y axis title
       -goutfile            string     Output file for non interactive displays
       -gdirectory          string     Output directory

       "-outfile" associated qualifiers
       -odirectory          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

Standard (Mandatory) qualifiers | Allowed values | Default
--- | --- | ---
[-seqall] (Parameter 1) | Sequence database USA | Readable sequence(s) | Required
-graph | Graph type | EMBOSS has a list of known devices, including postscript, ps, hpgl, hp7470, hp7580, meta, colourps, cps, xwindows, x11, tektronics, tekt, tek4107t, tek, none, null, text, data, xterm, png, xml | EMBOSS_GRAPHICS value, or x11
-outfile | Output file name | Output file | <sequence>.charge
Additional (Optional) qualifiers | Allowed values | Default
-window | Window | Integer 1 or more | 5
Advanced (Unprompted) qualifiers | Allowed values | Default
-aadata | Amino acid property data file name | Data file | Eamino.dat
-plot | Produce graphic | Toggle value Yes/No | No

## Input file format

charge reads in a protein sequence.

### Input files for usage example

'tsw:hbb_human' is a sequence entry in the example protein database 'tsw'

### Database entry: tsw:hbb_human

    ID   HBB_HUMAN      STANDARD;      PRT;   146 AA.
    AC   P02023;
    DT   21-JUL-1986 (Rel. 01, Created)
    DT   21-JUL-1986 (Rel. 01, Last sequence update)
    DT   15-JUL-1999 (Rel. 38, Last annotation update)
    DE   HEMOGLOBIN BETA CHAIN.
    GN   HBB.
    OS   Homo sapiens (Human), Pan troglodytes (Chimpanzee), and
    OS   Pan paniscus (Pygmy chimpanzee) (Bonobo).
    OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Mammalia;
    OC   Eutheria; Primates; Catarrhini; Hominidae; Homo.
    RN   [1]
    RP   SEQUENCE.
    RC   SPECIES=HUMAN;
    RA   BRAUNITZER G., GEHRING-MULLER R., HILSCHMANN N., HILSE K., HOBOM G.,
    RA   RUDLOFF V., WITTMANN-LIEBOLD B.;
    RT   "The constitution of normal adult human haemoglobin.";
    RL   Hoppe-Seyler's Z. Physiol. Chem. 325:283-286(1961).
    RN   [2]
    RP   SEQUENCE FROM N.A.
    RC   SPECIES=HUMAN;
    RX   MEDLINE; 81064667.
    RA   LAWN R.M., EFSTRATIADIS A., O'CONNELL C., MANIATIS T.;
    RT   "The nucleotide sequence of the human beta-globin gene.";
    RL   Cell 21:647-651(1980).
    RN   [3]
    RP   SEQUENCE OF 121-146 FROM N.A.
    RC   SPECIES=HUMAN;
    RX   MEDLINE; 85205333.
    RA   LANG K.M., SPRITZ R.A.;
    RT   "Cloning specific complete polyadenylylated 3'-terminal cDNA
    RT   segments.";
    RL   Gene 33:191-196(1985).
    RN   [4]
    RP   X-RAY CRYSTALLOGRAPHY (2.5 ANGSTROMS) OF DEOXYHEMOGLOBIN.
    RC   SPECIES=HUMAN;
    RX   MEDLINE; 76027820.
    RA   FERMI G.;
    RT   "Three-dimensional fourier synthesis of human deoxyhaemoglobin at
    RT   2.5-A resolution: refinement of the atomic model.";
    RL   J. Mol. Biol. 97:237-256(1975).
    RN   [5]
    RP   SEQUENCE.
    RC   SPECIES=P.TROGLODYTES;
    RX   MEDLINE; 66071496.
    RA   RIFKIN D.B., KONIGSBERG W.;
    RT   "The characterization of the tryptic peptides from the hemoglobin of
    RT   the chimpanzee (Pan troglodytes).";
    RL   Biochim. Biophys. Acta 104:457-461(1965).
    RN   [6]

      [Part of this file has been deleted for brevity]

    FT   VARIANT     140    140       A -> T (IN ST JACQUES: O2 AFFINITY UP).
    FT                                /FTId=VAR_003081.
    FT   VARIANT     140    140       A -> V (IN PUTTELANGE; POLYCYTHEMIA;
    FT                                O2 AFFINITY UP).
    FT                                /FTId=VAR_003082.
    FT   VARIANT     141    141       L -> R (IN OLMSTED; UNSTABLE).
    FT                                /FTId=VAR_003083.
    FT   VARIANT     142    142       A -> D (IN OHIO; O2 AFFINITY UP).
    FT                                /FTId=VAR_003084.
    FT   VARIANT     143    143       H -> D (IN RANCHO MIRAGE).
    FT                                /FTId=VAR_003085.
    FT   VARIANT     143    143       H -> Q (IN LITTLE ROCK; O2 AFFINITY UP).
    FT                                /FTId=VAR_003086.
    FT   VARIANT     143    143       H -> P (IN SYRACUSE; O2 AFFINITY UP).
    FT                                /FTId=VAR_003087.
    FT   VARIANT     143    143       H -> R (IN ABRUZZO; O2 AFFINITY UP).
    FT                                /FTId=VAR_003088.
    FT   VARIANT     144    144       K -> E (IN MITO; O2 AFFINITY UP).
    FT                                /FTId=VAR_003089.
    FT   VARIANT     145    145       Y -> C (IN RAINIER; O2 AFFINITY UP).
    FT                                /FTId=VAR_003090.
    FT   VARIANT     145    145       Y -> H (IN BETHESDA; O2 AFFINITY UP).
    FT                                /FTId=VAR_003091.
    FT   VARIANT     146    146       H -> D (IN HIROSHIMA; O2 AFFINITY UP).
    FT                                /FTId=VAR_003092.
    FT   VARIANT     146    146       H -> L (IN COWTOWN; O2 AFFINITY UP).
    FT                                /FTId=VAR_003093.
    FT   VARIANT     146    146       H -> P (IN YORK; O2 AFFINITY UP).
    FT                                /FTId=VAR_003094.
    FT   VARIANT     146    146       H -> Q (IN KODAIRA; O2 AFFINITY UP).
    FT                                /FTId=VAR_003095.
    FT   HELIX         5     15
    FT   TURN         16     17
    FT   HELIX        20     34
    FT   HELIX        36     41
    FT   HELIX        43     45
    FT   HELIX        51     55
    FT   TURN         56     56
    FT   HELIX        58     75
    FT   TURN         76     77
    FT   HELIX        78     94
    FT   TURN         95     96
    FT   TURN        100    100
    FT   HELIX       101    121
    FT   HELIX       124    142
    FT   TURN        143    144
    SQ   SEQUENCE   146 AA;  15867 MW;  EC9744C9 CRC32;
         VHLTPEEKSA VTALWGKVNV DEVGGEALGR LLVVYPWTQR FFESFGDLST PDAVMGNPKV
         KAHGKKVLGA FSDGLAHLDN LKGTFATLSE LHCDKLHVDP ENFRLLGNVL VCVLAHHFGK
         EFTPPVQAAY QKVVAGVANA LAHKYH
    //

## Output file format

If the option '-plot' is specified then charge displays a graph of the charge along the sequence otherwise it writes out a file containing the charges within a window starting at each position along the sequence.

The output file contains two columns separated by space or TAB characters. The first column is the position of the start of the window. The second column is the charge of the amino acids within that window.

### Output files for usage example

### File: hbb_human.charge

    CHARGE of HBB_HUMAN from 1 to 146: window 5

    Position	Charge
    1		0.100
    2		-0.100
    3		-0.400
    4		-0.200
    5		-0.200
    6		-0.200
    7		0.000
    8		0.200
    9		0.000
    10		0.000
    11		0.000
    12		0.000
    13		0.200
    14		0.200
    15		0.200
    16		0.200
    17		0.000
    18		-0.400
    19		-0.400
    20		-0.400
    21		-0.400
    22		-0.400
    23		-0.200
    24		-0.200
    25		-0.200
    26		0.000
    27		0.200
    28		0.200
    29		0.200
    30		0.200
    31		0.000
    32		0.000
    33		0.000
    34		0.000
    35		0.000
    36		0.200
    37		0.200
    38		0.200
    39		0.000
    40		0.000
    41		-0.200
    42		-0.200
    43		-0.400
    44		-0.200
    45		-0.200
    46		-0.200
    47		-0.200

      [Part of this file has been deleted for brevity]

    92		0.100
    93		0.100
    94		0.100
    95		0.100
    96		-0.100
    97		-0.300
    98		-0.400
    99		-0.400
    100		0.000
    101		0.000
    102		0.200
    103		0.200
    104		0.200
    105		0.000
    106		0.000
    107		0.000
    108		0.000
    109		0.000
    110		0.000
    111		0.000
    112		0.100
    113		0.200
    114		0.200
    115		0.200
    116		0.400
    117		0.100
    118		0.000
    119		0.000
    120		0.000
    121		-0.200
    122		0.000
    123		0.000
    124		0.000
    125		0.000
    126		0.000
    127		0.000
    128		0.200
    129		0.200
    130		0.200
    131		0.200
    132		0.200
    133		0.000
    134		0.000
    135		0.000
    136		0.000
    137		0.000
    138		0.000
    139		0.100
    140		0.300
    141		0.300
    142		0.400

## Data files

charge reads the data file 'Eamino.dat' to find the charge of the amino acids in the protein.

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

None.

## References

None.

## Warnings

None.

## Diagnostic Error Messages

None.

## Exit status

It always exits with status 0.

## Known bugs

None.

## See also

Program name | Description
--- | ---
backtranseq | Back translate a protein sequence
checktrans | Reports STOP codons and ORF statistics of a protein
compseq | Count composition of dimer/trimer/etc words in a sequence
emowse | Protein identification by mass spectrometry
freak | Residue/base frequency table or plot
iep | Calculates the isoelectric point of a protein
mwcontam | Shows molwts that match across a set of files
mwfilter | Filter noisy molwts from mass spec output
octanol | Displays protein hydropathy
pepinfo | Plots simple amino acid properties in parallel
pepstats | Protein statistics
pepwindow | Displays protein hydropathy
pepwindowall | Displays protein hydropathy of a set of sequences

## Author(s)

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

## History

Written (March 2001) - Alan Bleasby.

## Target users

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

## Comments

None