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Summary

Bio::Restriction::IO::itype2 - itype2 enzyme set

Package variables

Included modules

Inherit

Bio::Restriction::IO::base

Synopsis

Do not use this module directly. Use it via the Bio::Restriction::IO class.

Description

This is tab delimited, entry per line format which is fast to process.

Methods

Methods description

 Title   : read
 Usage   : $renzs = $stream->read
 Function: reads all the restrction enzymes from the stream
 Returns : a Bio::Restriction::IO object
 Args    : none

 Title   : _xln_sub
 Function: Translates withrefm coords to Bio::Restriction coords
 Args    : Bio::Restriction::Enzyme object, scalar integer (cut posn)
 Note    : Used internally; pass as a coderef to the B:R::Enzyme 
           constructor

 Title   : write
 Usage   : $stream->write($renzs)
 Function: writes restriction enzymes into the stream
 Returns : 1 for success and 0 for error
 Args    : a Bio::Restriction::Enzyme
           or a Bio::Restriction::EnzymeCollection object

Methods code

sub read {

    my $self = shift;

    my $renzs = Bio::Restriction::EnzymeCollection->new(-empty => 1);

    # read until start of data
    while (defined( my $line = $self->_readline()) ) {
        next if $line =~ /^[ R]/;
        $self->_pushback($line);
        last;
    }

    # enzyme name [tab] prototype [tab] recognition sequence with
    # cleavage site [tab] methylation site and type [tab] commercial
    # source [tab] references

    while (defined(my $line = $self->_readline()) ) {
        $self->debug($line);
        chomp $line;

        my ($name, $prototype, $site, $meth, $vendor, $refs) = split /\t/, $line;
        # we need mininum name and site
        unless ($site) {
            $self->warn("Can not parse line with name [$name]") if $self->verbose > 0;
            next;
        }
        next unless $name;

#         # four cut enzymes are not in this format
#         my $precut;
#         if ($site =~ m/^\((\d+\/\d+)\)[ATGCN]+/) {
#             $precut=$1;
#             $site =~ s/\($precut\)//;
#         }
        # -------------- cut ---------------

	# this regexp now parses all possible components
	# $1 : (s/t) or undef 
	# $2 : [site]
	# $3 : (m/n) or undef /maj

	my ($precut, $recog, $postcut) = ( $site =~ m/^(?:\((\w+\/\w+)\))?([\w^]+)(?:\((\w+\/\w+)\))?/ );


        my @sequences;
        if ($site =~ /\,/) {
            @sequences = split( /\,/, $site);
            $site=shift @sequences;
        }

        #
        # prototype 
        #
        
        # presence of a name means the prototype isoschizomer, absence means
        # this enzyme is the prototype
	my $is_prototype = ($prototype ? 1 : 0);


        #
        # vendors
        #
	my @vendors;
            @vendors = ( split / */, $vendor) if $vendor;

        #
        # references
        #
	my @refs;
        @refs = map {split /\n+/} $refs if $refs;

	# when enz is constructed, site() will contain original characters,
	# but recog() will contain a regexp if required.../maj

        my $re = Bio::Restriction::Enzyme->new(
	    -name          => $name,
	    -site          => $recog,
	    -recog         => $recog,
	    -precut        => $precut,
	    -postcut       => $postcut,
	    -is_prototype  => $is_prototype,
	    -prototype     => $prototype,
	    -vendors       => [@vendors],
	    -references    => [@refs],
	    -xln_sub       =>\& _xln_sub
	    );

        #
        # methylation
        #
        # [easier to set here during parsing than in constructor] /maj
        my @meths;
        if ($meth) {
            # this can be either X(Y) or X(Y),X2(Y2)
            # where X is the base and y is the type of methylation
            if ( $meth =~ /(\S+)\((\d+)\),(\S+)\((\d+)\)/ ) { # two msites per site
                #my ($p1, $m1, $p2, $m2) = ($1, $2, $3, $4);
                $re->methylation_sites($self->_meth($re,$1, $2),
                                       $self->_meth($re,$3,$4));
            }
            elsif ($meth =~ /(\S+)\((\d+)\)/ ) { # one msite per site or more sites
                #print Dumper $meth;
                $re->methylation_sites( $self->_meth($re,$1,$2) );
                @meths = split (/, /, $meth);
                $meth=shift @meths;
            } else {
                $self->warn("Unknown methylation format [$meth]") if $self->verbose >0;
            }
        }

        #
        # create special types of Enzymes
        #
        $self->_make_multisites( $re,\@ sequences,\@ meths) if @sequences;
        $renzs->enzymes($re);


    }

    return $renzs;

}

sub _xln_sub {

     my ($z,$c) = @_; 
    return ($c < 0 ? $c : length($z->string)+$c);

}

sub write {

    my ($self,@h) = @_;
    $self->throw_not_implemented;
}

1;

}

General documentation

User feedback is an integral part of the evolution of this and other
Bioperl modules. Send your comments and suggestions preferably to the
Bioperl mailing lists Your participation is much appreciated.

  bioperl-l@bioperl.org                  - General discussion
  http://bioperl.org/wiki/Mailing_lists  - About the mailing lists

Please direct usage questions or support issues to the mailing list:
bioperl-l@bioperl.org
rather than to the module maintainer directly. Many experienced and
reponsive experts will be able look at the problem and quickly
address it. Please include a thorough description of the problem
with code and data examples if at all possible.

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:

  https://redmine.open-bio.org/projects/bioperl/

Rob Edwards, redwards@utmem.edu

Heikki Lehvaslaiho, heikki-at-bioperl-dot-org
Mark A. Jensen, maj-at-fortinbras-dot-us

The rest of the documentation details each of the object
methods. Internal methods are usually preceded with a _