Bio::Tools::Run::StandAloneBlast - Object for the local execution of the NCBI BLAST program suite (blastall, blastpgp, bl2seq). There is experimental support for WU-Blast and NCBI rpsblast.
# Local-blast "factory object" creation and blast-parameter # initialization: @params = (-database => 'swissprot',-outfile => 'blast1.out'); $factory = Bio::Tools::Run::StandAloneBlast->new(@params); # Blast a sequence against a database: $str = Bio::SeqIO->new(-file=>'t/amino.fa', -format => 'Fasta'); $input = $str->next_seq(); $input2 = $str->next_seq(); $blast_report = $factory->blastall($input); # Run an iterated Blast (psiblast) of a sequence against a database: $factory->j(3); # 'j' is blast parameter for # of iterations $factory->outfile('psiblast1.out'); $factory = Bio::Tools::Run::StandAloneBlast->new(@params); $blast_report = $factory->blastpgp($input); # Use blast to align 2 sequences against each other: $factory = Bio::Tools::Run::StandAloneBlast->new(-outfile => 'bl2seq.out'); $factory->bl2seq($input, $input2); # Experimental support for WU-Blast 2.0 my $factory = Bio::Tools::Run::StandAloneBlast->new(-program =>"wublastp", -database =>"swissprot", -e => 1e-20); my $blast_report = $factory->wublast($seq); # Experimental support for NCBI rpsblast my $factory = Bio::Tools::Run::StandAloneBlast->new(-db => 'CDD/Cog', -expect => 0.001); $factory->F('T'); # turn on SEG filtering of query sequence my $blast_report = $factory->rpsblast($seq); # Various additional options and input formats are available, # see the DESCRIPTION section for details.
This DESCRIPTION only documents Bio::Tools::Run::StandAloneBlast: - a Bioperl object for running the NCBI standAlone BLAST package. Blast, itself, is a large & complex program - for more information regarding BLAST, please see the BLAST documentation which accompanies the BLAST distribution. BLAST is available from ftp://ncbi.nlm.nih.gov/blast/.
A source of confusion in documenting a BLAST interface is that the term "program" is used in - at least - three different ways in the BLAST documentation. In this DESCRIPTION, "program" will refer to the BLAST routine set by the BLAST -p parameter that can be set to blastn, blastp, tblastx etc. We will use the term Blast "executable" to refer to the various different executable files that may be called - ie blastall, blastpgp or bl2seq. In addition, there are several BLAST capabilities, which are also referred to as "programs", and are implemented by using specific combinations of BLAST executables, programs and parameters. They will be referred by their specific names - eg PSIBLAST and PHIBLAST.
-p
Before running StandAloneBlast it is necessary: to install BLAST on your system, to edit set the environmental variable $BLASTDIR or your $PATH variable to point to the BLAST directory, and to ensure that users have execute privileges for the BLAST program.
If the databases which will be searched by BLAST are located in the data subdirectory of the blast program directory (the default installation location), StandAloneBlast will find them; however, if the database files are located in any other location, environmental variable $BLASTDATADIR will need to be set to point to that directory.
The use of the StandAloneBlast module is as follows: Initially, a local blast "factory object" is created. The constructor may be passed an optional array of (non-default) parameters to be used by the factory, eg:
@params = (-program => 'blastn', -database => 'ecoli.nt'); $factory = Bio::Tools::Run::StandAloneBlast->new(@params);
Any parameters not explicitly set will remain as the defaults of the BLAST executable. Note each BLAST executable has somewhat different parameters and options. See the BLAST Documentation for a description or run the BLAST executable from the command line followed solely with a "-" to see a list of options and default values for that executable; eg >blastall -.
BLAST parameters can be changed and/or examined at any time after the factory has been created. The program checks that any parameter/switch being set/read is valid. Except where specifically noted, StandAloneBlast uses the same single-letter, case-sensitive parameter names as the actual blast program. Currently no checks are included to verify that parameters are of the proper type (e.g. string or numeric) or that their values are within the proper range.
As an example, to change the value of the Blast parameter 'e' ('e' is the parameter for expectation-value cutoff)
$expectvalue = 0.01; $factory->e($expectvalue);
Note that for improved script readibility one can modify the name of the BLAST parameters as desired as long as the initial letter (and case) of the parameter are preserved, e.g.:
$factory->expectvalue($expectvalue);
Unfortunately, some of the BLAST parameters are not the single letter one might expect (eg "iteration round" in blastpgp is 'j'). Again one can check by using, for example:
> blastpgp - .
Once the factory has been created and the appropriate parameters set, one can call one of the supported blast executables. The input sequence(s) to these executables may be fasta file(s) as described in the BLAST documentation.
$inputfilename = 't/testquery.fa'; $blast_report = $factory->blastall($inputfilename);
In addition, sequence input may be in the form of either a Bio::Seq object or or an array of Bio::Seq objects, e.g.:
$input = Bio::Seq->new(-id => "test query", -seq => "ACTACCCTTTAAATCAGTGGGGG"); $blast_report = $factory->blastall($input);
For blastall and non-psiblast blastpgp runs, report object is either a Bio::Tools::BPlite or Bio::SearchIO object, selected by the user with the parameter _READMETHOD. The leading underscore is needed to distinguish this option from options which are passed to the BLAST executable. The default parser is Bio::SearchIO::blast. If BPlite method is selected, Bio::Tools::BPlite objects will be returned for standard blast and Bio::Tools::BPpsilite for a multiple-iteration blasts, and a Bio::Tools::BPbl2seq for bl2seq. In any case, the "raw" blast report is also available. The filename is set by the in the 'outfile' parameter and has the default value of "blastreport.out". The BPlite method is only provided to support legacy code since the BPlite modules are no longer maintained - do not use BPlite since these modules will be removed eventually.
For psiblast execution in the BLAST "jumpstart" mode, the program must be passed (in addition to the query sequence itself) an alignment containing the query sequence (in the form of a SimpleAlign object) as well as a "mask" specifying at what residues position-specific scoring matrices (PSSMs) are to used and at what residues default scoring matrices (eg BLOSUM) are to be used. See psiblast documentation for more details. The mask itself is a string of 0's and 1's which is the same length as each sequence in the alignment and has a "1" at locations where (PSSMs) are to be used and a "0" at all other locations. So for example:
$str = Bio::AlignIO->new(-file => "cysprot.msf", -format => 'msf'); $aln = $str->next_aln(); $len = $aln->length_aln(); $mask = '1' x $len; # simple case where PSSM's to be used at all residues $report = $factory->blastpgp("cysprot1.fa", $aln, $mask);
For bl2seq execution, StandAloneBlast.pm can be combined with AlignIO.pm to directly produce a SimpleAlign object from the alignment of the two sequences produced by bl2seq as in:
# Get 2 sequences $str = Bio::SeqIO->new(-file=>'t/amino.fa' , -format => 'Fasta'); my $seq3 = $str->next_seq(); my $seq4 = $str->next_seq(); # Run bl2seq on them $factory = Bio::Tools::Run::StandAloneBlast->new(-program => 'blastp', -outfile => 'bl2seq.out'); my $bl2seq_report = $factory->bl2seq($seq3, $seq4); # Use AlignIO.pm to create a SimpleAlign object from the bl2seq report $str = Bio::AlignIO->new(-file=> 'bl2seq.out',-format => 'bl2seq'); $aln = $str->next_aln();
For more examples of syntax and use of Blast.pm, the user is encouraged to run the scripts standaloneblast.pl in the bioperl examples/tools directory and StandAloneBlast.t in the bioperl t/ directory.
User feedback is an integral part of the evolution of this and other Bioperl modules. Send your comments and suggestions preferably to one of the Bioperl mailing lists. Your participation is much appreciated.
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Report bugs to the Bioperl bug tracking system to help us keep track the bugs and their resolution. Bug reports can be submitted via the web:
http://bugzilla.open-bio.org/
Email schattner at alum.mit.edu
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The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _
Essentially all BLAST parameter can be set via StandAloneBlast.pm. Some of the most commonly used parameters are listed below. All parameters have defaults and are optional (I think.) For a complete listing of settable parameters, run the relevant executable BLAST program with the option "-" as in blastall -
-p Program Name [String] Input should be one of "blastp", "blastn", "blastx", "tblastn", or "tblastx". -d Database [String] default = nr The database specified must first be formatted with formatdb. Multiple database names (bracketed by quotations) will be accepted. An example would be -d "nr est" -i Query File [File In] Set by StandAloneBlast.pm from script. default = stdin. The query should be in FASTA format. If multiple FASTA entries are in the input file, all queries will be searched. -e Expectation value (E) [Real] default = 10.0 -o BLAST report Output File [File Out] Optional, default = ./blastreport.out ; set by StandAloneBlast.pm -S Query strands to search against database (for blast[nx], and tblastx). 3 is both, 1 is top, 2 is bottom [Integer] default = 3
-j is the maximum number of rounds (default 1; i.e., regular BLAST) -h is the e-value threshold for including sequences in the score matrix model (default 0.001) -c is the "constant" used in the pseudocount formula specified in the paper (default 10) -B Multiple alignment file for PSI-BLAST "jump start mode" Optional -Q Output File for PSI-BLAST Matrix in ASCII [File Out] Optional
-d Database [String] default = (none - you must specify a database) The database specified must first be formatted with formatdb. Multiple database names (bracketed by quotations) will be accepted. An example would be -d "Cog Smart" -i Query File [File In] Set by StandAloneBlast.pm from script. default = stdin. The query should be in FASTA format. If multiple FASTA entries are in the input file, all queries will be searched. -e Expectation value (E) [Real] default = 10.0 -o BLAST report Output File [File Out] Optional, default = ./blastreport.out ; set by StandAloneBlast.pm
-i First sequence [File In] -j Second sequence [File In] -p Program name: blastp, blastn, blastx. For blastx 1st argument should be nucleotide [String] default = blastp -o alignment output file [File Out] default = stdout -e Expectation value (E) [Real] default = 10.0 -S Query strands to search against database (blastn only). 3 is both, 1 is top, 2 is bottom [Integer] default = 3
-p Program Name [String] Input should be one of "wublastp", "wublastn", "wublastx", "wutblastn", or "wutblastx". -d Database [String] default = nr The database specified must first be formatted with xdformat. -i Query File [File In] Set by StandAloneBlast.pm from script. default = stdin. The query should be in FASTA format. If multiple FASTA entries are in the input file, all queries will be searched. -E Expectation value (E) [Real] default = 10.0 -o BLAST report Output File [File Out] Optional, default = ./blastreport.out ; set by StandAloneBlast.pm
Title : quiet Usage : $obj->quiet($newval) Function: Example : Returns : value of quiet (a scalar) Args : on set, new value (a scalar or undef, optional)
Title : executable Usage : my $exe = $blastfactory->executable('blastall'); Function: Finds the full path to the 'codeml' executable Returns : string representing the full path to the exe Args : [optional] name of executable to set path to [optional] boolean flag whether or not warn when exe is not found
Title : program_path Usage : my $path = $factory->program_path(); Function: Builds path for executable Returns : string representing the full path to the exe Args : none
Title : program_dir Usage : my $dir = $factory->program_dir(); Function: Abstract get method for dir of program. Returns : string representing program directory Args : none
Title : blastall Usage : $blast_report = $factory->blastall('t/testquery.fa'); or $input = Bio::Seq->new(-id=>"test query", -seq=>"ACTACCCTTTAAATCAGTGGGGG"); $blast_report = $factory->blastall($input); or $seq_array_ref = \@seq_array; # where @seq_array is an array of Bio::Seq objects $blast_report = $factory->blastall(\@seq_array); Returns : Reference to a Blast object or BPlite object containing the blast report. Args : Name of a file or Bio::Seq object or an array of Bio::Seq object containing the query sequence(s). Throws an exception if argument is not either a string (eg a filename) or a reference to a Bio::Seq object (or to an array of Seq objects). If argument is string, throws exception if file corresponding to string name can not be found.
Title : wublast Usage : $blast_report = $factory->wublast('t/testquery.fa'); or $input = Bio::Seq->new(-id=>"test query", -seq=>"ACTACCCTTTAAATCAGTGGGGG"); $blast_report = $factory->wublast($input); or $seq_array_ref = \@seq_array; # where @seq_array is an array of Bio::Seq objects $blast_report = $factory->wublast(\@seq_array); Returns : Reference to a Blast object Args : Name of a file or Bio::Seq object or an array of Bio::Seq object containing the query sequence(s). Throws an exception if argument is not either a string (eg a filename) or a reference to a Bio::Seq object (or to an array of Seq objects). If argument is string, throws exception if file corresponding to string name can not be found.
Title : blastpgp Usage : $blast_report = $factory-> blastpgp('t/testquery.fa'); or $input = Bio::Seq->new(-id=>"test query", -seq=>"ACTADDEEQQPPTCADEEQQQVVGG"); $blast_report = $factory->blastpgp ($input); or $seq_array_ref = \@seq_array; # where @seq_array is an array of Bio::Seq objects $blast_report = $factory-> blastpgp(\@seq_array); Returns : Reference to a Bio::SearchIO object or BPlite object containing the blast report (BPlite only if you specify _READMETHOD=> 'BPlite') Args : Name of a file or Bio::Seq object. In psiblast jumpstart mode two additional arguments are required: a SimpleAlign object one of whose elements is the query and a "mask" to determine how BLAST should select scoring matrices see DESCRIPTION above for more details. Throws an exception if argument is not either a string (eg a filename) or a reference to a Bio::Seq object (or to an array of Seq objects). If argument is string, throws exception if file corresponding to string name can not be found. Returns : Reference to Bio::SearchIO object or Bio::Tools::BPpsilite if you specify _READMETHOD => 'BPlite' object containing the blast report.
Title : rpsblast Usage : $blast_report = $factory->rpsblast('t/testquery.fa'); or $input = Bio::Seq->new(-id=>"test query", -seq=>"MVVLCRADDEEQQPPTCADEEQQQVVGG"); $blast_report = $factory->rpsblast($input); or $seq_array_ref = \@seq_array; # where @seq_array is an array of Bio::Seq objects $blast_report = $factory->rpsblast(\@seq_array); Args : Name of a file or Bio::Seq object or an array of Bio::Seq object containing the query sequence(s). Throws an exception if argument is not either a string (eg a filename) or a reference to a Bio::Seq object (or to an array of Seq objects). If argument is string, throws exception if file corresponding to string name can not be found. Returns : Reference to a Bio::SearchIO object or BPlite object containing the blast report (BPlite only if you specify _READMETHOD=> 'BPlite')
Title : bl2seq Usage : $factory-> bl2seq('t/seq1.fa', 't/seq2.fa'); or $input1 = Bio::Seq->new(-id=>"test query1", -seq=>"ACTADDEEQQPPTCADEEQQQVVGG"); $input2 = Bio::Seq->new(-id=>"test query2", -seq=>"ACTADDEMMMMMMMDEEQQQVVGG"); $blast_report = $factory->bl2seq ($input1, $input2); Returns : Reference to a BPbl2seq object containing the blast report. Args : Names of 2 files or 2 Bio::Seq objects containing the sequences to be aligned by bl2seq. Throws an exception if argument is not either a pair of strings (eg filenames) or references to Bio::Seq objects. If arguments are strings, throws exception if files corresponding to string names can not be found.
Title : _generic_local_blast Usage : internal function not called directly Returns : Bio::SearchIO or Bio::Tools::BPlite object Args : Reference to calling object and name of BLAST executable
Title : _generic_local_wublast Usage : internal function not called directly Returns : Blast object Args : Reference to calling object and name of BLAST executable
Title : _runblast Usage : Internal function, not to be called directly Function: makes actual system call to Blast program Example : Returns : Report object in the appropriate format (Bio::SearchIO) or if BPlite is requested: Bio::Tools::BPlite, Bio::Tools::BPpsilite,or Bio::Tools::BPbl2seq) Args : Reference to calling object, name of BLAST executable, and parameter string for executable
Title : _runwublast Usage : Internal function, not to be called directly Function: makes actual system call to WU-Blast program Example : Returns : Report Blast object Args : Reference to calling object, name of BLAST executable, and parameter string for executable
Title : _setinput Usage : Internal function, not to be called directly Function: Create input file(s) for Blast executable Example : Returns : name of file containing Blast data input Args : Seq object reference or input file name
Title : _setparams Usage : Internal function, not to be called directly Function: Create parameter inputs for Blast program Example : Returns : parameter string to be passed to Blast Args : Reference to calling object and name of BLAST executable
Title : no_param_checks Usage : $obj->no_param_checks($newval) Function: Boolean flag as to whether or not we should trust the sanity checks for parameter values Returns : value of no_param_checks Args : newvalue (optional)
Title : save_tempfiles Usage : $obj->save_tempfiles($newval) Function: Returns : value of save_tempfiles Args : newvalue (optional)
Title : outfile_name Usage : my $outfile = $tcoffee->outfile_name(); Function: Get/Set the name of the output file for this run (if you wanted to do something special) Returns : string Args : [optional] string to set value to
Title : tempdir Usage : my $tmpdir = $self->tempdir(); Function: Retrieve a temporary directory name (which is created) Returns : string which is the name of the temporary directory Args : none
Title : cleanup Usage : $tcoffee->cleanup(); Function: Will cleanup the tempdir directory after a PAML run Returns : none Args : none
Title : io Usage : $obj->io($newval) Function: Gets a Bio::Root::IO object Returns : Bio::Root::IO Args : none
To install Bio::Seq, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Bio::Seq
CPAN shell
perl -MCPAN -e shell install Bio::Seq
For more information on module installation, please visit the detailed CPAN module installation guide.