252 lines
9.9 KiB
Plaintext
Executable File
252 lines
9.9 KiB
Plaintext
Executable File
ps_scan documentation
|
|
=====================
|
|
|
|
Reference:
|
|
Alexandre Gattiker, Elisabeth Gasteiger, Amos Bairoch.
|
|
ScanProsite: a reference implementation of a PROSITE scanning tool.
|
|
Applied Bioinformatics 2002:1(2) 107-108.
|
|
|
|
Contact: prosite@expasy.org
|
|
|
|
ps_scan is a perl program used to scan one or several patterns, rules and/or
|
|
profiles from PROSITE against one or several protein sequnces in Swiss-Prot or
|
|
FASTA format. It requires two compiled external programs from the PFTOOLS
|
|
package : "pfscan" used to scan a sequence against a profile library and
|
|
"psa2msa" which is necessary for the "-o msa" output format only.
|
|
|
|
Authors:
|
|
Alexandre Gattiker
|
|
Edouard de Castro; E-mail: ecastro@sib.swiss
|
|
Elisabeth Gasteiger
|
|
|
|
Installation
|
|
------------
|
|
|
|
Download a binary package for your platform from
|
|
|
|
https://ftp.expasy.org/databases/prosite/ps_scan/ps_scan_<platform>.tar.gz
|
|
|
|
or the source packages from
|
|
|
|
https://ftp.vital-it.ch/pub/software/unix/pftools/ or https://github.com/sib-swiss/pftools3
|
|
|
|
in which case you will need gcc or a compatible fortran compiler to compile the
|
|
pftools sources, see https://ftp.expasy.org/databases/prosite/README.pftools.
|
|
|
|
You may need to edit the ps_scan.pl to provide absolute paths to the directory
|
|
where you have installed the pfscan and psa2msa executables, unless you have
|
|
stored them in a directory in your PATH.
|
|
|
|
A local copy of the PROSITE database is also needed. You may download it
|
|
in a single file from
|
|
|
|
https://ftp.expasy.org/databases/prosite/prosite.dat
|
|
|
|
Usage
|
|
-----
|
|
|
|
perl ps_scan.pl [options] sequence-file(s)
|
|
ps_scan version $VERSION options:
|
|
-h : this help screen
|
|
Input/Output:
|
|
-e : specify the ID or AC of an entry in sequence-file
|
|
-o : specify an output format : $formats_string
|
|
-d : specify a prosite.dat file
|
|
-p : specify a pattern or the AC of a prosite motif
|
|
-f : specify a motif AC to scan against together with all its
|
|
releated post-processing motifs (but show only specified
|
|
motif hits)
|
|
Selection:
|
|
-r : do not scan profiles
|
|
-m : only scan profiles
|
|
-s : skip frequently matching (unspecific) patterns and profiles
|
|
-l : cut-off level for profiles (default : 0)
|
|
Pattern match mode:
|
|
-x : specify maximum number of accepted matches of X's in sequence
|
|
(default=0)
|
|
-g : Turn greediness off
|
|
-v : Turn overlaps off
|
|
-i : Allow included matches
|
|
|
|
The sequence-file may be in Swiss-Prot or FASTA format.
|
|
If no PROSITE file is submitted, it will be searched in the paths
|
|
$PROSITE/prosite.dat and $SPROT/prosite/prosite.dat.
|
|
There may be several -d, -p and -q arguments.
|
|
|
|
Pfsearch options:
|
|
-w pfsearch : Compares a query profile against a protein sequence library.
|
|
A profile file must be specified with option -d.
|
|
|
|
$progname -w pfsearch [-C cutoff] [-R] -d profile-file seq-library-file(s)
|
|
|
|
-R: use raw scores rather than normalized scores for match selection
|
|
-C=# : Cut-off value. Reports only match score higher than the specified
|
|
parameter.
|
|
An integer argument is interpreted as a raw score value,
|
|
a decimal argument as a normalized score value. An integer value forces
|
|
option -R.
|
|
|
|
|
|
Output formats
|
|
--------------
|
|
|
|
An output format may be specified with the -o option. Here are the available
|
|
formats, with an example output with a profile :
|
|
|
|
-o scan : default ps_scan output format.
|
|
|
|
YAHD_ECOLI : PS50088 ANK_REPEAT Ankyrin repeat profile.
|
|
12 - 37 -------LAAQQGDIDKVKTCLALGVDINTCDR L=-1
|
|
38 - 70 QGKTAITLASLYQQYACVQALIDAGADINKQDH L=0
|
|
138 - 175 VGWTPLLEAIVLNDGGikqqaIVQLLLEHGASPHLTDK L=0
|
|
176 - 201 YGKTPLELARERGFEEIAQLLIAAGA------- L=0
|
|
|
|
-o fasta : matching sequences in FASTA format.
|
|
|
|
>YAHD_ECOLI/12-37 : PS50088 ANK_REPEAT L=-1 Ankyrin repeat profile.
|
|
LAAQQGDIDKVKTCLALGVDINTCDR
|
|
>YAHD_ECOLI/38-70 : PS50088 ANK_REPEAT L=0 Ankyrin repeat profile.
|
|
QGKTAITLASLYQQYACVQALIDAGADINKQDH
|
|
>YAHD_ECOLI/138-175 : PS50088 ANK_REPEAT L=0 Ankyrin repeat profile.
|
|
VGWTPLLEAIVLNDGGIKQQAIVQLLLEHGASPHLTDK
|
|
>YAHD_ECOLI/176-201 : PS50088 ANK_REPEAT L=0 Ankyrin repeat profile.
|
|
YGKTPLELARERGFEEIAQLLIAAGA
|
|
|
|
-o psa : profile-to-sequence-alignments with insertions in lowercase and
|
|
deletions marked as dashes.
|
|
|
|
>YAHD_ECOLI/12-37 : PS50088 ANK_REPEAT L=-1 Ankyrin repeat profile.
|
|
-------LAAQQGDIDKVKTCLALGVDINTCDR
|
|
>YAHD_ECOLI/38-70 : PS50088 ANK_REPEAT L=0 Ankyrin repeat profile.
|
|
QGKTAITLASLYQQYACVQALIDAGADINKQDH
|
|
>YAHD_ECOLI/138-175 : PS50088 ANK_REPEAT L=0 Ankyrin repeat profile.
|
|
VGWTPLLEAIVLNDGGikqqaIVQLLLEHGASPHLTDK
|
|
>YAHD_ECOLI/176-201 : PS50088 ANK_REPEAT L=0 Ankyrin repeat profile.
|
|
YGKTPLELARERGFEEIAQLLIAAGA-------
|
|
|
|
-o msa : multiple sequence alignment of the matches in each sequence, built
|
|
from the psa format with gaps marked as dots.
|
|
|
|
>YAHD_ECOLI/12-37 : PS50088 ANK_REPEAT L=-1 Ankyrin repeat profile.
|
|
-------LAAQQGDID.....KVKTCLALGVDINTCDR
|
|
>YAHD_ECOLI/38-70 : PS50088 ANK_REPEAT L=0 Ankyrin repeat profile.
|
|
QGKTAITLASLYQQYA.....CVQALIDAGADINKQDH
|
|
>YAHD_ECOLI/138-175 : PS50088 ANK_REPEAT L=0 Ankyrin repeat profile.
|
|
VGWTPLLEAIVLNDGGikqqaIVQLLLEHGASPHLTDK
|
|
>YAHD_ECOLI/176-201 : PS50088 ANK_REPEAT L=0 Ankyrin repeat profile.
|
|
YGKTPLELARERGFEE.....IAQLLIAAGA-------
|
|
|
|
-o pff : tabular format listing bounding positions on the sequence and the
|
|
profile, the raw and normalized profile score, and the cut-off level.
|
|
|
|
YAHD_ECOLI 12 37 ANK_REPEAT 8 -1 196 6.653 -1
|
|
YAHD_ECOLI 38 70 ANK_REPEAT 1 -1 351 10.793 0
|
|
YAHD_ECOLI 138 175 ANK_REPEAT 1 -1 288 9.110 0
|
|
YAHD_ECOLI 176 201 ANK_REPEAT 1 -8 343 10.579 0
|
|
|
|
Pattern and rule matches are reported in the same formats, but cut-off levels
|
|
are not available. In scan, psa and msa output formats, amino acids matching an
|
|
"x" in the pattern are reported in lowercase. In pff format only the first
|
|
three columns are available. The "-o matchlist" output format is specific to
|
|
patterns and not meant for public use.
|
|
|
|
|
|
Profile and pattern matching parameters
|
|
---------------------------------------
|
|
|
|
Several parameters can be fine-tuned.
|
|
|
|
- profile cut-off levels (-l option)
|
|
|
|
Most profiles contain several cut-off levels. The level 0 cut-off is the
|
|
trusted cut-off for positive matches, but a level -1 is usually defined above
|
|
which a match is potential, especially if there are other matches in the
|
|
sequence with the profile. By default, pfscan is run with the cut-off
|
|
level 0, so that only trusted matches are reported. To retrieve potential
|
|
(weak) matches as well, run ps_scan with the option "-l -1". Weak matches
|
|
are then reported with the indication "L=-1".
|
|
|
|
- skip frequently matching patterns (-s option)
|
|
|
|
Some PROSITE entries such as those describing commonly found post-
|
|
translational modifications (a typical example is N-glycosylation) are found
|
|
in the majority of known protein sequences. While it is generally useful to
|
|
note their presence, some programs may want, in some cases, to ignore those
|
|
entries, which contain the line "CC /SKIP-FLAG=TRUE;".
|
|
|
|
Pattern match mode:
|
|
|
|
- pattern greediness off (-g option)
|
|
|
|
A pattern-matching engine is said to be "greedy" if it tries to extend at
|
|
most variable-length pattern elements. The sequence "ABCDC" and the pattern
|
|
"A-x(1,3)-C" will produce the match "ABCDC" with a greedy engine, and the
|
|
match "ABC" with a non-greedy one. By default, PROSITE is scanned in greedy
|
|
mode, unless the -g option is set.
|
|
|
|
- overlaps (-v option) and included matches (-i option)
|
|
|
|
Some patterns may produce distinct but overlapping matches on a given
|
|
sequence. Additionally, if the pattern contains variable-length elements,
|
|
some of these matches may be completely included in another one. Different
|
|
combinations of -g, -v and -i options may produce differences in match count
|
|
and match positions with patterns that contain variable-length elements. An
|
|
engine which allows overlaps should be greedy in order to reduce the number
|
|
of multiple hits which are almost entirely overlapping except at the
|
|
extremities.
|
|
|
|
- treatment of X characters in sequences (-x option)
|
|
|
|
The PROSITE syntax describes how to treat ambiguities in the pattern, but not
|
|
how to handle ambiguities in the sequence. In rare sequences in Swiss-Prot
|
|
and other databases, the characters B and Z are used according to IUBMB
|
|
nomenclature when a residue may be either Asp or Asn, or Glu or Gln,
|
|
respectively. The ps_scan program will produce a match if the sequence has a
|
|
"B" and the pattern allows either a "D" or a "N", or both (and similarly for
|
|
Z).
|
|
|
|
Whether the character X should be allowed to match any position of a pattern
|
|
is more controversial. It is generally useful to accept a single pattern
|
|
position to match X (unless that pattern position is an X itself, in which
|
|
case we can accept more). The maximum number of X characters which are
|
|
allowed to match a non-X position in a pattern can be specified with the -x
|
|
option. The default value is 0.
|
|
|
|
Examples
|
|
--------
|
|
|
|
examples :
|
|
|
|
scan 1 sequence with 1 pattern
|
|
perl ps_scan.pl -p PS00123 seq.dat
|
|
perl ps_scan.pl -p "P-S-[QW]" seq.dat
|
|
|
|
scan 1 sequence with all prosite, including profiles
|
|
perl ps_scan.pl seq.dat
|
|
|
|
scan 2 profiles or patterns against swiss-prot
|
|
perl ps_scan.pl -p PS00123 -p PS00124 sprot.dat
|
|
|
|
scan all patterns and rules against swiss-prot
|
|
perl ps_scan.pl -r sprot.dat
|
|
|
|
scan a profile file against a sequence file
|
|
perl ps_scan.pl -d profile.prf sprot.dat
|
|
|
|
License
|
|
-------
|
|
|
|
The ps_scan program and the Prosite.pm module are Copyright (C) 2001-2006,
|
|
Swiss Institute of Bioinformatics. They are released under the
|
|
terms of the GNU General Public License, available at
|
|
http://www.gnu.org/copyleft/gpl.html.
|
|
|
|
This program is free software; you can redistribute it and/or modify it under
|
|
the terms of the GNU General Public License as published by the Free Software
|
|
Foundation; either version 2 of the License, or (at your option) any later
|
|
version.
|
|
|
|
This program is distributed in the hope that it will be useful, but WITHOUT ANY
|
|
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
|
|
PARTICULAR PURPOSE. See the GNU General Public License for more details.
|