/ 
bioperl-1.4
/ Bio::Restriction::EnzymeCollection

NAME

Bio::Restriction::EnzymeCollection - Set of restriction endonucleases

SYNOPSIS

use Bio::Restriction::EnzymeCollection;

# create a set with a default enzymes
my $collection = Bio::Restriction::EnzymeCollection;


print "No of enzymes: ", scalar $collection->each_enzyme, "\n";

# find something about a particular enzyme
my $enz=$collection->get_enzyme('EcoRI');

# and we know about some special types of enzymes.
my $blunt_collection = $collection->blunt_enzymes; # enzymes without an overhang

# see 'CUSTOM COLLECTIONS' below  for more options

# the most common selection criteria is how many times the enzymes
# cuts. This can be estimated using the length and specificity of
# the recognition site

# enzymes that have euivalent of  6bp recognition sequence
my $six_cutters=$collection->cutters(6);

# all rare cutters
my $rare_cutters=$collection->cutters(-start=>6, -end=>8);

DESCRIPTION

Bio::Restriction::EnzymeCollection represents a collection of restriction enzymes.

If you create a new collection directly rather than from a REBASE format file using Bio::RestrictionIO, it will be populated by a default set of protype, typeII enzymes with site and cut information only.

Use Bio::Restriction::Analysis to figure out which enzymes are available and where they cut your sequence.

CUSTOM COLLECTIONS

Note, that the underlying Enzyme objects are much more rich and allow more complicated selections than the predefinend methods. The way to create a custom subset is as follows:

my $initial_collection;
my $new_collection = Bio::Restriction::EnzymeCollection(-empty => 1);
foreach $enzyme ($initial_collection) {
    # this selects only type II enzymes
    $new_collection($enzyme) if $enzyme->type eq 'II';
}

COMMENTS

I am trying to make this backwards compatible with Bio::Tools::RestrictionEnzyme. Undoubtedly some things will break, but we can fix things as we progress.....!

I have added another comments section at the end of this POD that discusses a couple of areas I know are broken (at the moment)

SEE ALSO

Bio::Restriction::IO - read in enzymes from REBASE files (s

Bio::Restriction::Analysis - figure out what enzymes cut a sequence (start here)

Bio::Restriction::Enzyme - defining a single restriction enzyme

FEEDBACK

Mailing Lists

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.

bioperl-l@bioperl.org             - General discussion
http://bioperl.org/MailList.shtml - About the mailing lists

Reporting Bugs

Report bugs to the Bioperl bug tracking system to help us keep track the bugs and their resolution. Bug reports can be submitted via email or the web:

bioperl-bugs@bio.perl.org
http://bugzilla.bioperl.org/

AUTHOR

Rob Edwards, redwards@utmem.edu

CONTRIBUTORS

Heikki Lehvaslaiho, heikki@ebi.ac.uk

COPYRIGHT

Copyright (c) 2003 Rob Edwards.

Some of this work is Copyright (c) 1997-2002 Steve A. Chervitz. All Rights Reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

APPENDIX

Methods beginning with a leading underscore are considered private and are intended for internal use by this module. They are not considered part of the public interface and are described here for documentation purposes only.

new

Title     : new
Function  : Initializes the Restriction::EnzymeCollection object
Returns   : The Restriction::EnzymeCollection object
Arguments : optional named parameter -empty

Set parameter -empty to true if you do NOT want the collection be populated by the default set of prototype type II enzymes.

Alternatively, pass an array of enzymes to -enzymes parameter.

Manipulate the enzymes within the collection

enzymes

Title     : enzyme
Function  : add/get method for enzymes and enzyme collections
Returns   : object itself
Arguments : array of Bio::Restriction::Enzyme and
            Bio::Restriction::EnzymeCollection objects

each_enzyme

Title     : each_enzyme
Function  : get an array of enzymes
Returns   : array of Bio::Restriction::Enzyme objects
Arguments : -

get_enzyme

Title     : get_enzyme
Function  : Gets a Bio::Restriction::Enzyme object for the enzyme name
Returns   : A Bio::Restriction::Enzyme object or undef
Arguments : An enzyme name that is in the collection

available_list

Title     : available_list
Function  : Gets a list of all the enzymes that we know about
Returns   : A reference to an array with all the enzyme names
            that we have defined or 0 if none are defined
Arguments : Nothing
Comments  : Note, I maintain this for backwards compatibility,
            but I don't like the name as it is very ambiguous

longest_cutter

Title     : longest_cutter
Function  : Gets the enzyme with the longest recognition site
Returns   : A Bio::Restriction::Enzyme object
Arguments : Nothing
Comments  : Note, this is used by Bio::Restriction::Analysis
            to figure out what to do with circular sequences

Filter enzymes

blunt_enzymes

Title     : blunt_enzymes
Function  : Gets a list of all the enzymes that are blunt cutters
Returns   : A reference to an array with all the enzyme names that
            are blunt cutters or 0 if none are defined
Arguments : Nothing
Comments  :

This is an example of the kind of filtering better done by the scripts using the rich collection of methods in Bio::Restriction::Enzyme.

cutters

Title     : cutters
Function  : Gets a list of all the enzymes that recognize a
            certain size, e.g. 6-cutters
Usage     : $cutters = $collection->cutters(6);
Returns   : A reference to an array with all the enzyme names
            that are x cutters or 0 if none are defined
Arguments : A positive number for the size of cutters to return
            OR
            A range: (-start => 6, -end => 8,
                      -inclusive => 1, -exclusive = 0 )

The default for a range is 'inclusive'