
                                  plotcon 



Function

   Plot conservation of a sequence alignment

Description

   plotcon reads a sequence alignment and draws a plot of the sequence
   conservation within windows over the alignment.

Algorithm

   Sequence conservation is calculated for windows of a specified length
   over the alignment. Within a window, the similarity of any one
   position is taken to be the average of all the possible pairwise
   substitution scores of the bases or residues at that position. The
   pairwise substitution scores are taken from the specified similarity
   matrix. The average of the position similarities within the window is
   plotted.

   The average similarity is calculated by:

Av. Sim. =       sum( Mij*wi + Mji*wj  )
                      -------------------
                  (Nseq*Wsize)*((Nseq-1)*Wsize)

sum - over column*window size
w - sequence weighting
M - matrix comparison table
i,j - with respect to residue i or j
Nseq - number of sequences in the alignment
Wsize - window size

Usage

   Here is a sample session with plotcon


% plotcon -sformat msf globins.msf -graph cps 
Plot conservation of a sequence alignment
Window size [4]: 

Created plotcon.ps

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

Command line arguments

   Standard (Mandatory) qualifiers:
  [-sequences]         seqset     File containing a sequence alignment
   -winsize            integer    [4] Number of columns to average alignment
                                  quality over. The larger this value is, the
                                  smoother the plot will be. (Any integer
                                  value)
   -graph              xygraph    [$EMBOSS_GRAPHICS value, or x11] Graph type
                                  (ps, hpgl, hp7470, hp7580, meta, cps, x11,
                                  tekt, tek, none, data, xterm, png, gif)

   Additional (Optional) qualifiers:
   -scorefile          matrix     [EBLOSUM62 for protein, EDNAFULL for DNA]
                                  This is the scoring matrix file used when
                                  comparing sequences. By default it is the
                                  file 'EBLOSUM62' (for proteins) or the file
                                  'EDNAFULL' (for nucleic sequences). These
                                  files are found in the 'data' directory of
                                  the EMBOSS installation.

   Advanced (Unprompted) qualifiers: (none)
   Associated qualifiers:

   "-sequences" 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
   -gdesc              string     Graph description
   -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

   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

   plotcon reads a set of gapped, aligned sequences.

  Input files for usage example

  File: globins.msf

!!AA_MULTIPLE_ALIGNMENT 1.0

  ../data/globins.msf MSF:  164 Type: P 25/06/01 CompCheck: 4278 ..

  Name: HBB_HUMAN Len: 164  Check: 6914 Weight: 0.61
  Name: HBB_HORSE Len: 164  Check: 6007 Weight: 0.65
  Name: HBA_HUMAN Len: 164  Check: 3921 Weight: 0.65
  Name: HBA_HORSE Len: 164  Check: 4770 Weight: 0.83
  Name: MYG_PHYCA Len: 164  Check: 7930 Weight: 1.00
  Name: GLB5_PETMA Len: 164  Check: 1857 Weight: 0.91
  Name: LGB2_LUPLU Len: 164  Check: 2879 Weight: 0.43

//

           1                                               50
HBB_HUMAN  ~~~~~~~~VHLTPEEKSAVTALWGKVN.VDEVGGEALGR.LLVVYPWTQR
HBB_HORSE  ~~~~~~~~VQLSGEEKAAVLALWDKVN.EEEVGGEALGR.LLVVYPWTQR
HBA_HUMAN  ~~~~~~~~~~~~~~VLSPADKTNVKAA.WGKVGAHAGEYGAEALERMFLS
HBA_HORSE  ~~~~~~~~~~~~~~VLSAADKTNVKAA.WSKVGGHAGEYGAEALERMFLG
MYG_PHYCA  ~~~~~~~VLSEGEWQLVLHVWAKVEAD.VAGHGQDILIR.LFKSHPETLE
GLB5_PETMA PIVDTGSVAPLSAAEKTKIRSAWAPVYSTYETSGVDILVKFFTSTPAAQE
LGB2_LUPLU ~~~~~~~~GALTESQAALVKSSWEEFNANIPKHTHRFFILVLEIAPAAKD

           51                                             100
HBB_HUMAN  FFESFGDLSTPDAVMGNPKVKAHGKKVLGAFSDGLAHLDNLKGTFATLSE
HBB_HORSE  FFDSFGDLSNPGAVMGNPKVKAHGKKVLHSFGEGVHHLDNLKGTFAALSE
HBA_HUMAN  FPTTKTYFPHFDLSHGSAQVKGHGKKVADALTNAVAHVDDMPNALSALSD
HBA_HORSE  FPTTKTYFPHFDLSHGSAQVKAHGKKVGDALTLAVGHLDDLPGALSNLSD
MYG_PHYCA  KFDRFKHLKTEAEMKASEDLKKHGVTVLTALGAILKKKGHHEAELKPLAQ
GLB5_PETMA FFPKFKGLTTADQLKKSADVRWHAERIINAVNDAVASMDDTEKMSMKLRD
LGB2_LUPLU LFSFLKGTSEVPQNNPELQAHAGKVFKLVYEAAIQLQVTGVVVTDATLKN

           101                                            150
HBB_HUMAN  LHCDKLH..VDPENFRLLGNVLVCVLAHHFGKEFTPPVQAAYQKVVAGVA
HBB_HORSE  LHCDKLH..VDPENFRLLGNVLVVVLARHFGKDFTPELQASYQKVVAGVA
HBA_HUMAN  LHAHKLR..VDPVNFKLLSHCLLVTLAAHLPAEFTPAVHASLDKFLASVS
HBA_HORSE  LHAHKLR..VDPVNFKLLSHCLLSTLAVHLPNDFTPAVHASLDKFLSSVS
MYG_PHYCA  SHATKHK..IPIKYLEFISEAIIHVLHSRHPGDFGADAQGAMNKALELFR
GLB5_PETMA LSGKHAK..SFQVDPQYFKVLAAVIADTVAAGDAGFEKLMSMICILLRSA
LGB2_LUPLU LGSVHVSKGVADAHFPVVKEAILKTIKEVVGAKWSEELNSAWTIAYDELA

           151        164
HBB_HUMAN  NALAHKYH~~~~~~
HBB_HORSE  NALAHKYH~~~~~~
HBA_HUMAN  TVLTSKYR~~~~~~
HBA_HORSE  TVLTSKYR~~~~~~
MYG_PHYCA  KDIAAKYKELGYQG
GLB5_PETMA Y~~~~~~~~~~~~~
LGB2_LUPLU IVIKKEMNDAA~~~

Output file format

   A graph of the quality of the alignment is dispalyed on the specifed
   graphics device.

  Output files for usage example

  Graphics File: plotcon.ps

   [plotcon results]

Data files

   It reads in the specified similarity matrix.

   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

   The program is useful for visualising the quality of alignment along
   its length. This can give a qualitative insight into where there are
   regions of conservation in a group of aligned sequences.

   Note that you should only compare the results of two runs of plotcon
   if you use the same window size in each. This is because the
   'similarity score' units that are output are very sensitive to the
   size of the window. A large window (e.g. 100) gives a nice, smooth
   curve, and very low 'similarity score' units, whereas a small window
   (e.g. 4) gives a very spikey, noisy plot with 'similarity score' units
   of a round 1.00

References

   None.

Warnings

   plotcon does not distinguish between aligned and unaligned sets of
   sequences. If the input set of sequences is unaligned, the output will
   in most cases lack much biological meaning.

Diagnostic Error Messages

   None.

Exit status

   It always exits with status 0.

Known bugs

   None.

See also

   Program name Description
   edialign Local multiple alignment of sequences
   emma Multiple sequence alignment (ClustalW wrapper)
   infoalign Display basic information about a multiple sequence
   alignment
   prettyplot Draw a sequence alignment with pretty formatting
   showalign Display a multiple sequence alignment in pretty format
   tranalign Generate an aligment of nucleic coding regions from aligned
   proteins

Author(s)

   Tim Carver (tcarver © rfcgr.mrc.ac.uk)
   MRC Rosalind Franklin Centre for Genomics Research Wellcome Trust
   Genome Campus, Hinxton, Cambridge, CB10 1SB, UK

History

   Written (Sept 2000) - Tim Carver.

Target users

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

Comments

   None
