EMBOSS: pepwindow

pepwindow

Function

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Description

pepwindow draws a classic Kyte & Doolittle hydropathy plot for a protein sequence.

Algorithm

pepwindow calculates hydropathy in windows of a specified size over the input sequence.

Usage

Command line arguments

Input file format

pepwindow reads any protein sequence USA.

Output file format

An image is displayed on the specified graphics device.

Data files

pepwindow reads the Kyte-Doolittle hydropathy data from the file 'Enakai.dat'

The EMBOSS data file 'Enakai.dat' contains :-

D Hydropathy index (Kyte-Doolittle, 1982)
R 0807099
A Kyte, J. and Doolittle, R.F.
T A simple method for displaying the hydropathic character of a protein
J J. Mol. Biol. 157, 105-132 (1982)
C CHOC760103    0.964  JANJ780102    0.922  DESM900102    0.898
  EISD860103    0.897  CHOC760104    0.889  WOLR810101    0.885
  RADA880101    0.884  MANP780101    0.881  EISD840101    0.878
  PONP800103    0.870  NAKH920108    0.868  JANJ790101    0.867
  JANJ790102    0.866  PONP800102    0.861  MEIH800103    0.856
  PONP800101    0.851  PONP800108    0.850  WARP780101    0.845
  RADA880108    0.842  ROSG850102    0.841  DESM900101    0.837
  BIOV880101    0.829  RADA880107    0.828  LIFS790102    0.824
  KANM800104    0.824  CIDH920104    0.824  MIYS850101    0.821
  RADA880104    0.819  NAKH900111    0.817  NISK800101    0.812
  FAUJ830101    0.811  ARGP820103    0.806  NAKH920105    0.803
  ARGP820102    0.803  KRIW790101   -0.805  CHOC760102   -0.838
  GUYH850101   -0.843  RACS770102   -0.844  JANJ780103   -0.845
  ROSM880101   -0.845  PRAM900101   -0.850  JANJ780101   -0.852
  GRAR740102   -0.859  MEIH800102   -0.871  ROSM880102   -0.878
  OOBM770101   -0.899
I   A/L    R/K    N/M    D/F    C/P    Q/S    E/T    G/W    H/Y    I/V
    1.8   -4.5   -3.5   -3.5    2.5   -3.5   -3.5   -0.4   -3.2    4.5
    3.8   -3.9    1.9    2.8   -1.6   -0.8   -0.7   -0.9   -1.3    4.2
//

pepwindow can use any of the "Nakai et al." database of amino acid parameters - these used to be in a database called "NAKAI" but are now in one called "AAINDEX". EMBOSS has a program aaindexextract that takes data from this database and makes it available for pepwindow.

1. FTP the AAINDEX database from Japan:
ftp://ftp.genome.ad.jp/pub/db/genomenet/aaindex/aaindex1

2. Run aaindexextract with the aaindex1 file as input (or ask whoever installs EMBOSS to run it)

3. Run pepwindow with -datafile specifying the name of whatever "AAINDEX" datafile you wish to use. (Use embossdata -showall to see your available "AAINDEX" data file names.)

Notes

None.

References

Kyte, J. and Doolittle, R.F.
A simple method for displaying the hydropathic character of a protein
J. Mol. Biol. 157, 105-132 (1982)

Warnings

In calculating hydropathy, pepwindow can use any of the amino acid parameters from the database of "Nakai et al." which are now included in the database AAINDEX. Before running pepwindow, you must first extract the required data files from AAINDEX (see "Data Files" section).

Diagnostic Error Messages

None.

Exit status

0 upon successful completion.

Known bugs

None. pepwindow can use any of the "Nakai et al." database of amino acid parameters - these are in a database called "AAINDEX". The program aaindexextract takes data from this database and makes it available for pepwindow.