NAME

FAST::Bio::Seq - Sequence object, with features

SYNOPSIS

    # This is the main sequence object in Bioperl

    # gets a sequence from a file
    $seqio  = FAST::Bio::SeqIO->new( '-format' => 'embl' , -file => 'myfile.dat');
    $seqobj = $seqio->next_seq();

    # SeqIO can both read and write sequences; see FAST::Bio::SeqIO
    # for more information and examples

    # get from database
    $db = FAST::Bio::DB::GenBank->new();
    $seqobj = $db->get_Seq_by_acc('X78121');

    # make from strings in script
    $seqobj = FAST::Bio::Seq->new( -display_id => 'my_id',
			     -seq => $sequence_as_string);

    # gets sequence as a string from sequence object
    $seqstr   = $seqobj->seq(); # actual sequence as a string
    $seqstr   = $seqobj->subseq(10,50); # slice in biological coordinates

    # retrieves information from the sequence
    # features must implement FAST::Bio::SeqFeatureI interface

    @features = $seqobj->get_SeqFeatures(); # just top level
    foreach my $feat ( @features ) {
	print "Feature ",$feat->primary_tag," starts ",$feat->start," ends ",
	$feat->end," strand ",$feat->strand,"\n";

        # features retain link to underlying sequence object
        print "Feature sequence is ",$feat->seq->seq(),"\n"
    }

    # sequences may have a species

    if( defined $seq->species ) {
	print "Sequence is from ",$species->binomial," [",$species->common_name,"]\n";
    }

    # annotation objects are FAST::Bio::AnnotationCollectionI's
    $ann      = $seqobj->annotation(); # annotation object

    # references is one type of annotations to get. Also get
    # comment and dblink. Look at FAST::Bio::AnnotationCollection for
    # more information

    foreach my $ref ( $ann->get_Annotations('reference') ) {
	print "Reference ",$ref->title,"\n";
    }

    # you can get truncations, translations and reverse complements, these
    # all give back FAST::Bio::Seq objects themselves, though currently with no
    # features transfered

    my $trunc = $seqobj->trunc(100,200);
    my $rev   = $seqobj->revcom();

    # there are many options to translate - check out the docs
    my $trans = $seqobj->translate();

    # these functions can be chained together

    my $trans_trunc_rev = $seqobj->trunc(100,200)->revcom->translate();

DESCRIPTION

A Seq object is a sequence with sequence features placed on it. The Seq object contains a PrimarySeq object for the actual sequence and also implements its interface.

In Bioperl we have 3 main players that people are going to use frequently

FAST::Bio::PrimarySeq  - just the sequence and its names, nothing else.
FAST::Bio::SeqFeatureI - a feature on a sequence, potentially with a sequence
                   and a location and annotation.
FAST::Bio::Seq         - A sequence and a collection of sequence features
                   (an aggregate) with its own annotation.

Although Bioperl is not tied heavily to file formats these distinctions do map to file formats sensibly and for some bioinformaticians this might help

FAST::Bio::PrimarySeq  - Fasta file of a sequence
FAST::Bio::SeqFeatureI - A single entry in an EMBL/GenBank/DDBJ feature table
FAST::Bio::Seq         - A single EMBL/GenBank/DDBJ entry

By having this split we avoid a lot of nasty circular references (sequence features can hold a reference to a sequence without the sequence holding a reference to the sequence feature). See FAST::Bio::PrimarySeq and FAST::Bio::SeqFeatureI for more information.

Ian Korf really helped in the design of the Seq and SeqFeature system.

Examples

A simple and fundamental block of code:

use FAST::Bio::SeqIO;

my $seqIOobj = FAST::Bio::SeqIO->new(-file=>"1.fa"); # create a SeqIO object
my $seqobj = $seqIOobj->next_seq;              # get a Seq object

With the Seq object in hand one has access to a powerful set of Bioperl methods and related Bioperl objects. This next script will take a file of sequences in EMBL format and create a file of the reverse-complemented sequences in Fasta format using Seq objects. It also prints out details about the exons it finds as sequence features in Genbank Flat File format.

  use FAST::Bio::Seq;
  use FAST::Bio::SeqIO;

  $seqin = FAST::Bio::SeqIO->new( -format => 'EMBL' , -file => 'myfile.dat');
  $seqout= FAST::Bio::SeqIO->new( -format => 'Fasta', -file => '>output.fa');

  while((my $seqobj = $seqin->next_seq())) {
      print "Seen sequence ",$seqobj->display_id,", start of seq ",
            substr($seqobj->seq,1,10),"\n";
      if( $seqobj->alphabet eq 'dna') {
	    $rev = $seqobj->revcom;
	    $id  = $seqobj->display_id();
            $id  = "$id.rev";
            $rev->display_id($id);
            $seqout->write_seq($rev);
      }

      foreach $feat ( $seqobj->get_SeqFeatures() ) {
           if( $feat->primary_tag eq 'exon' ) {
              print STDOUT "Location ",$feat->start,":",
                    $feat->end," GFF[",$feat->gff_string,"]\n";
	   }
      }
  }

Let's examine the script. The lines below import the Bioperl modules. Seq is the main Bioperl sequence object and SeqIO is the Bioperl support for reading sequences from files and to files

use FAST::Bio::Seq;
use FAST::Bio::SeqIO;

These two lines create two SeqIO streams: one for reading in sequences and one for outputting sequences:

$seqin = FAST::Bio::SeqIO->new( -format => 'EMBL' , -file => 'myfile.dat');
$seqout= FAST::Bio::SeqIO->new( -format => 'Fasta', -file => '>output.fa');

Notice that in the "$seqout" case there is a greater-than sign, indicating the file is being opened for writing.

Using the

'-argument' => value

syntax is common in Bioperl. The file argument is like an argument to open() . You can also pass in filehandles or FileHandle objects by using the -fh argument (see FAST::Bio::SeqIO documentation for details). Many formats in Bioperl are handled, including Fasta, EMBL, GenBank, Swissprot (swiss), PIR, and GCG.

$seqin = FAST::Bio::SeqIO->new( -format => 'EMBL' , -file => 'myfile.dat');
$seqout= FAST::Bio::SeqIO->new( -format => 'Fasta', -file => '>output.fa');

This is the main loop which will loop progressively through sequences in a file, and each call to $seqio->next_seq() provides a new Seq object from the file:

while((my $seqobj = $seqio->next_seq())) {

This print line below accesses fields in the Seq object directly. The $seqobj->display_id is the way to access the display_id attribute of the Seq object. The $seqobj->seq method gets the actual sequence out as string. Then you can do manipulation of this if you want to (there are however easy ways of doing truncation, reverse-complement and translation).

print "Seen sequence ",$seqobj->display_id,", start of seq ",
             substr($seqobj->seq,1,10),"\n";

Bioperl has to guess the alphabet of the sequence, being either 'dna', 'rna', or 'protein'. The alphabet attribute is one of these three possibilities.

if( $seqobj->alphabet eq 'dna') {

The $seqobj->revcom method provides the reverse complement of the Seq object as another Seq object. Thus, the $rev variable is a reference to another Seq object. For example, one could repeat the above print line for this Seq object (putting $rev in place of $seqobj). In this case we are going to output the object into the file stream we built earlier on.

$rev = $seqobj->revcom;

When we output it, we want the id of the outputted object to be changed to "$id.rev", ie, with .rev on the end of the name. The following lines retrieve the id of the sequence object, add .rev to this and then set the display_id of the rev sequence object to this. Notice that to set the display_id attribute you just need call the same method, display_id(), with the new value as an argument. Getting and setting values with the same method is common in Bioperl.

$id  = $seqobj->display_id();
$id  = "$id.rev";
$rev->display_id($id);

The write_seq method on the SeqIO output object, $seqout, writes the $rev object to the filestream we built at the top of the script. The filestream knows that it is outputting in fasta format, and so it provides fasta output.

$seqout->write_seq($rev);

This block of code loops over sequence features in the sequence object, trying to find ones who have been tagged as 'exon'. Features have start and end attributes and can be outputted in Genbank Flat File format, GFF, a standarized format for sequence features.

foreach $feat ( $seqobj->get_SeqFeatures() ) {
    if( $feat->primary_tag eq 'exon' ) {
        print STDOUT "Location ",$feat->start,":",
           $feat->end," GFF[",$feat->gff_string,"]\n";
    }
}

The code above shows how a few FAST::Bio::Seq methods suffice to read, parse, reformat and analyze sequences from a file. A full list of methods available to FAST::Bio::Seq objects is shown below. Bear in mind that some of these methods come from PrimarySeq objects, which are simpler than Seq objects, stripped of features (see FAST::Bio::PrimarySeq for more information).

# these methods return strings, and accept strings in some cases:

$seqobj->seq();              # string of sequence
$seqobj->subseq(5,10);       # part of the sequence as a string
$seqobj->accession_number(); # when there, the accession number
$seqobj->alphabet();         # one of 'dna','rna',or 'protein'
$seqobj->version()           # when there, the version
$seqobj->keywords();         # when there, the Keywords line
$seqobj->length()            # length
$seqobj->desc();             # description
$seqobj->primary_id();       # a unique id for this sequence regardless
                             # of its display_id or accession number
$seqobj->display_id();       # the human readable id of the sequence

Some of these values map to fields in common formats. For example, The display_id() method returns the LOCUS name of a Genbank entry, the (\S+) following the > character in a Fasta file, the ID from a SwissProt file, and so on. The desc() method will return the DEFINITION line of a Genbank file, the description following the display_id in a Fasta file, and the DE field in a SwissProt file.

# the following methods return new Seq objects, but
# do not transfer features across to the new object:

$seqobj->trunc(5,10)  # truncation from 5 to 10 as new object
$seqobj->revcom       # reverse complements sequence
$seqobj->translate    # translation of the sequence

# if new() can be called this method returns 1, else 0

$seqobj->can_call_new

# the following method determines if the given string will be accepted
# by the seq() method - if the string is acceptable then validate()
# returns 1, or 0 if not

$seqobj->validate_seq($string)

# the following method returns or accepts a Species object:

$seqobj->species();

Please see FAST::Bio::Species for more information on this object.

# the following method returns or accepts an Annotation object
# which in turn allows access to Annotation::Reference
# and Annotation::Comment objects:

$seqobj->annotation();

These annotations typically refer to entire sequences, unlike features. See FAST::Bio::AnnotationCollectionI, FAST::Bio::Annotation::Collection, FAST::Bio::Annotation::Reference, and FAST::Bio::Annotation::Comment for details.

It is also important to be able to describe defined portions of a sequence. The combination of some description and the corresponding sub-sequence is called a feature - an exon and its coordinates within a gene is an example of a feature, or a domain within a protein.

# the following methods return an array of SeqFeatureI objects:

$seqobj->get_SeqFeatures # The 'top level' sequence features
$seqobj->get_all_SeqFeatures # All sequence features, including sub-seq
                             # features, such as features in an exon

# to find out the number of features use:

$seqobj->feature_count

Here are just some of the methods available to SeqFeatureI objects:

# these methods return numbers:

$feat->start          # start position (1 is the first base)
$feat->end            # end position (2 is the second base)
$feat->strand         # 1 means forward, -1 reverse, 0 not relevant

# these methods return or accept strings:

$feat->primary_tag    # the name of the sequence feature, eg
                      # 'exon', 'glycoslyation site', 'TM domain'
$feat->source_tag     # where the feature comes from, eg, 'EMBL_GenBank',
                      # or 'BLAST'

# this method returns the more austere PrimarySeq object, not a
# Seq object - the main difference is that PrimarySeq objects do not
# themselves contain sequence features

$feat->seq            # the sequence between start,end on the
                      # correct strand of the sequence

See FAST::Bio::PrimarySeq for more details on PrimarySeq objects.

# useful methods for feature comparisons, for start/end points

$feat->overlaps($other)  # do $feat and $other overlap?
$feat->contains($other)  # is $other completely within $feat?
$feat->equals($other)    # do $feat and $other completely agree?

# one can also add features

$seqobj->add_SeqFeature($feat)     # returns 1 if successful
$seqobj->add_SeqFeature(@features) # returns 1 if successful

# sub features. For complex join() statements, the feature
# is one sequence feature with many sub SeqFeatures

$feat->sub_SeqFeature  # returns array of sub seq features

Please see FAST::Bio::SeqFeatureI and FAST::Bio::SeqFeature::Generic, for more information on sequence features.

It is worth mentioning that one can also retrieve the start and end positions of a feature using a FAST::Bio::LocationI object:

$location = $feat->location # $location is a FAST::Bio::LocationI object
$location->start;           # start position
$location->end;             # end position

This is useful because one needs a FAST::Bio::Location::SplitLocationI object in order to retrieve the coordinates inside the Genbank or EMBL join() statements (e.g. "CDS join(51..142,273..495,1346..1474)"):

  if ( $feat->location->isa('FAST::Bio::Location::SplitLocationI') &&
	       $feat->primary_tag eq 'CDS' )  {
    foreach $loc ( $feat->location->sub_Location ) {
      print $loc->start . ".." . $loc->end . "\n";
    }
  }

See FAST::Bio::LocationI and FAST::Bio::Location::SplitLocationI for more information.

Implemented Interfaces

This class implements the following interfaces.

FAST::Bio::SeqI

Note that this includes implementing FAST::Bio::PrimarySeqI.

FAST::Bio::IdentifiableI
FAST::Bio::DescribableI
FAST::Bio::AnnotatableI
FAST::Bio::FeatureHolderI

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/wiki/Mailing_lists  - About the mailing lists

Support

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.

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 the web:

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

AUTHOR - Ewan Birney, inspired by Ian Korf objects

Email birney@ebi.ac.uk

CONTRIBUTORS

Jason Stajich E<lt>jason@bioperl.orgE<gt>
Mark A. Jensen maj -at- fortinbras -dot- us

APPENDIX

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

new

 Title   : new
 Usage   : $seq = FAST::Bio::Seq->new( -seq => 'ATGGGGGTGGTGGTACCCT',
                                 -id  => 'human_id',
				 -accession_number => 'AL000012',
			       );

 Function: Returns a new Seq object from
           basic constructors, being a string for the sequence
           and strings for id and accession_number
 Returns : a new FAST::Bio::Seq object

PrimarySeq interface

The PrimarySeq interface provides the basic sequence getting and setting methods for on all sequences.

These methods implement the FAST::Bio::PrimarySeq interface by delegating to the primary_seq inside the object. This means that you can use a Seq object wherever there is a PrimarySeq, and of course, you are free to use these functions anyway.

seq

Title   : seq
Usage   : $string = $obj->seq()
Function: Get/Set the sequence as a string of letters. The
          case of the letters is left up to the implementer.
          Suggested cases are upper case for proteins and lower case for
          DNA sequence (IUPAC standard),
          but implementations are suggested to keep an open mind about
          case (some users... want mixed case!)
Returns : A scalar
Args    : Optionally on set the new value (a string). An optional second
          argument presets the alphabet (otherwise it will be guessed).
          Both parameters may also be given in named parameter style
          with -seq and -alphabet being the names.

validate_seq

 Title   : validate_seq
 Usage   : if(! $seq->validate_seq($seq_str) ) {
                print "sequence $seq_str is not valid for an object of type ",
		      ref($seq), "\n";
	   }
 Function: Validates a given sequence string. A validating sequence string
           must be accepted by seq(). A string that does not validate will
           lead to an exception if passed to seq().

           The implementation provided here does not take alphabet() into
           account. Allowed are all letters (A-Z), '-','.','*','=', and '~'.

 Example :
 Returns : 1 if the supplied sequence string is valid for the object, and
           0 otherwise.
 Args    : The sequence string to be validated.

length

Title   : length
Usage   : $len = $seq->length()
Function:
Example :
Returns : Integer representing the length of the sequence.
Args    : None

Methods from the FAST::Bio::PrimarySeqI interface

subseq

Title   : subseq
Usage   : $substring = $obj->subseq(10,40);
Function: Returns the subseq from start to end, where the first base
          is 1 and the number is inclusive, ie 1-2 are the first two
          bases of the sequence

          Start cannot be larger than end but can be equal

Returns : A string
Args    : 2 integers

display_id

Title   : display_id
Usage   : $id = $obj->display_id or $obj->display_id($newid);
Function: Gets or sets the display id, also known as the common name of
          the Seq object.

          The semantics of this is that it is the most likely string
          to be used as an identifier of the sequence, and likely to
          have "human" readability.  The id is equivalent to the LOCUS
          field of the GenBank/EMBL databanks and the ID field of the
          Swissprot/sptrembl database. In fasta format, the >(\S+) is
          presumed to be the id, though some people overload the id
          to embed other information. Bioperl does not use any
          embedded information in the ID field, and people are
          encouraged to use other mechanisms (accession field for
          example, or extending the sequence object) to solve this.

          Notice that $seq->id() maps to this function, mainly for
          legacy/convenience issues.
Returns : A string
Args    : None or a new id

accession_number

Title   : accession_number
Usage   : $unique_biological_key = $obj->accession_number;
Function: Returns the unique biological id for a sequence, commonly
          called the accession_number. For sequences from established
          databases, the implementors should try to use the correct
          accession number. Notice that primary_id() provides the
          unique id for the implemetation, allowing multiple objects
          to have the same accession number in a particular implementation.

          For sequences with no accession number, this method should return
          "unknown".

          Can also be used to set the accession number.
Example : $key = $seq->accession_number or $seq->accession_number($key)
Returns : A string
Args    : None or an accession number

desc

Title   : desc
Usage   : $seqobj->desc($string) or $seqobj->desc()
Function: Sets or gets the description of the sequence
Example :
Returns : The description
Args    : The description or none

primary_id

Title   : primary_id
Usage   : $unique_implementation_key = $obj->primary_id;
Function: Returns the unique id for this object in this
          implementation. This allows implementations to manage
          their own object ids in a way the implementation can control
          clients can expect one id to map to one object.

          For sequences with no natural id, this method should return
          a stringified memory location.

          Can also be used to set the primary_id (or unset to undef).

          [Note this method name is likely to change in 1.3]

Example : $id = $seq->primary_id or $seq->primary_id($id)
Returns : A string
Args    : None or an id, or undef to unset the primary id.

can_call_new

 Title   : can_call_new
 Usage   : if ( $obj->can_call_new ) {
             $newobj = $obj->new( %param );
	   }
 Function: can_call_new returns 1 or 0 depending
           on whether an implementation allows new
           constructor to be called. If a new constructor
           is allowed, then it should take the followed hashed
           constructor list.

           $myobject->new( -seq => $sequence_as_string,
			   -display_id  => $id
			   -accession_number => $accession
			   -alphabet => 'dna',
			 );
 Example :
 Returns : 1 or 0
 Args    : None

alphabet

Title   : alphabet
Usage   : if ( $obj->alphabet eq 'dna' ) { /Do Something/ }
Function: Get/Set the type of sequence being one of
          'dna', 'rna' or 'protein'. This is case sensitive.

          This is not called <type> because this would cause
          upgrade problems from the 0.5 and earlier Seq objects.

Returns : A string either 'dna','rna','protein'. NB - the object must
          make a call of the type - if there is no type specified it
          has to guess.
Args    : optional string to set : 'dna' | 'rna' | 'protein'

is_circular

Title   : is_circular
Usage   : if( $obj->is_circular) { /Do Something/ }
Function: Returns true if the molecule is circular
Returns : Boolean value
Args    : none

Methods for FAST::Bio::IdentifiableI compliance

object_id

Title   : object_id
Usage   : $string    = $obj->object_id()
Function: a string which represents the stable primary identifier
          in this namespace of this object. For DNA sequences this
          is its accession_number, similarly for protein sequences

          This is aliased to accession_number().
Returns : A scalar

version

Title   : version
Usage   : $version    = $obj->version()
Function: a number which differentiates between versions of
          the same object. Higher numbers are considered to be
          later and more relevant, but a single object described
          the same identifier should represent the same concept

Returns : A number

authority

Title   : authority
Usage   : $authority    = $obj->authority()
Function: a string which represents the organisation which
          granted the namespace, written as the DNS name for
          organisation (eg, wormbase.org)

Returns : A scalar

namespace

Title   : namespace
Usage   : $string    = $obj->namespace()
Function: A string representing the name space this identifier
          is valid in, often the database name or the name
          describing the collection

Returns : A scalar

Methods for FAST::Bio::DescribableI compliance

display_name

Title   : display_name
Usage   : $string    = $obj->display_name()
Function: A string which is what should be displayed to the user
          the string should have no spaces (ideally, though a cautious
          user of this interface would not assumme this) and should be
          less than thirty characters (though again, double checking
          this is a good idea)

          This is aliased to display_id().
Returns : A scalar

description

Title   : description
Usage   : $string    = $obj->description()
Function: A text string suitable for displaying to the user a
          description. This string is likely to have spaces, but
          should not have any newlines or formatting - just plain
          text. The string should not be greater than 255 characters
          and clients can feel justified at truncating strings at 255
          characters for the purposes of display

          This is aliased to desc().
Returns : A scalar

Methods for implementing FAST::Bio::AnnotatableI

annotation

Title   : annotation
Usage   : $ann = $seq->annotation or 
          $seq->annotation($ann)
Function: Gets or sets the annotation
Returns : FAST::Bio::AnnotationCollectionI object
Args    : None or FAST::Bio::AnnotationCollectionI object

See FAST::Bio::AnnotationCollectionI and FAST::Bio::Annotation::Collection for more information

Methods for delegating FAST::Bio::AnnotationCollectionI

get_Annotations()

Usage   : my @annotations = $seq->get_Annotations('key')
Function: Retrieves all the FAST::Bio::AnnotationI objects for a specific key
          for this object
Returns : list of FAST::Bio::AnnotationI - empty if no objects stored for a key
Args    : string which is key for annotations

add_Annotation()

Usage   : $seq->add_Annotation('reference',$object);
          $seq->add_Annotation($object,'FAST::Bio::MyInterface::DiseaseI');
          $seq->add_Annotation($object);
          $seq->add_Annotation('disease',$object,'FAST::Bio::MyInterface::DiseaseI');
Function: Adds an annotation for a specific key for this sequence object.

          If the key is omitted, the object to be added must provide a value
          via its tagname().

          If the archetype is provided, this and future objects added under
          that tag have to comply with the archetype and will be rejected
          otherwise.

Returns : none
Args    : annotation key ('disease', 'dblink', ...)
          object to store (must be FAST::Bio::AnnotationI compliant)
          [optional] object archetype to map future storage of object
          of these types to

remove_Annotations()

Usage   : $seq->remove_Annotations()
Function: Remove the annotations for the specified key from this sequence 
          object
Returns : an list of FAST::Bio::AnnotationI compliant objects which were stored
          under the given key(s) for this sequence object
Args    : the key(s) (tag name(s), one or more strings) for which to
          remove annotations (optional; if none given, flushes all
          annotations)

get_num_of_annotations()

Usage   : my $count = $seq->get_num_of_annotations()
Alias   : num_Annotations
Function: Returns the count of all annotations stored for this sequence
          object      
Returns : integer
Args    : none

Methods to implement FAST::Bio::FeatureHolderI

This includes methods for retrieving, adding, and removing features.

get_SeqFeatures

Title   : get_SeqFeatures
Usage   :
Function: Get the feature objects held by this feature holder.

          Features which are not top-level are subfeatures of one or
          more of the returned feature objects, which means that you
          must traverse the subfeature arrays of each top-level
          feature object in order to traverse all features associated
          with this sequence.

          Top-level features can be obtained by tag, specified in 
          the argument.

          Use get_all_SeqFeatures() if you want the feature tree
          flattened into one single array.

Example :
Returns : an array of FAST::Bio::SeqFeatureI implementing objects
Args    : [optional] scalar string (feature tag)

get_all_SeqFeatures

Title   : get_all_SeqFeatures
Usage   : @feat_ary = $seq->get_all_SeqFeatures();
Function: Returns the tree of feature objects attached to this
          sequence object flattened into one single array. Top-level
          features will still contain their subfeature-arrays, which
          means that you will encounter subfeatures twice if you
          traverse the subfeature tree of the returned objects.

          Use get_SeqFeatures() if you want the array to contain only
          the top-level features.

Returns : An array of FAST::Bio::SeqFeatureI implementing objects.
Args    : None

feature_count

Title   : feature_count
Usage   : $seq->feature_count()
Function: Return the number of SeqFeatures attached to a sequence
Returns : integer representing the number of SeqFeatures
Args    : None

add_SeqFeature

Title   : add_SeqFeature
Usage   : $seq->add_SeqFeature($feat);
          $seq->add_SeqFeature(@feat);
Function: Adds the given feature object (or each of an array of feature
          objects to the feature array of this
          sequence. The object passed is required to implement the
          FAST::Bio::SeqFeatureI interface.
Returns : 1 on success
Args    : A FAST::Bio::SeqFeatureI implementing object, or an array of such objects.

remove_SeqFeatures

Title   : remove_SeqFeatures
Usage   : $seq->remove_SeqFeatures();
Function: Flushes all attached SeqFeatureI objects.

          To remove individual feature objects, delete those from the returned
          array and re-add the rest.
Example :
Returns : The array of FAST::Bio::SeqFeatureI objects removed from this seq.
Args    : None

Methods provided in the FAST::Bio::PrimarySeqI interface

These methods are inherited from the PrimarySeq interface and work as one expects, building new FAST::Bio::Seq objects or other information as expected. See FAST::Bio::PrimarySeq for more information.

Sequence Features are not transfered to the new objects. This is possibly a mistake. Anyone who feels the urge in dealing with this is welcome to give it a go.

revcom

Title   : revcom
Usage   : $rev = $seq->revcom()
Function: Produces a new FAST::Bio::Seq object which
          is the reversed complement of the sequence. For protein
          sequences this throws an exception of "Sequence is a protein.
          Cannot revcom"

          The id is the same id as the original sequence, and the
          accession number is also identical. If someone wants to track
          that this sequence has be reversed, it needs to define its own
          extensions

          To do an in-place edit of an object you can go:

          $seq = $seq->revcom();

          This of course, causes Perl to handle the garbage collection of
          the old object, but it is roughly speaking as efficient as an
          in-place edit.

Returns : A new (fresh) FAST::Bio::Seq object
Args    : None

trunc

Title   : trunc
Usage   : $subseq = $myseq->trunc(10,100);
Function: Provides a truncation of a sequence

Example :
Returns : A fresh Seq object
Args    : A Seq object

id

Title   : id
Usage   : $id = $seq->id()
Function: This is mapped on display_id
Returns : value of display_id()
Args    : [optional] value to update display_id

Seq only methods

These methods are specific to the FAST::Bio::Seq object, and not found on the FAST::Bio::PrimarySeq object

primary_seq

Title   : primary_seq
Usage   : $seq->primary_seq or $seq->primary_seq($newval)
Function: Get or set a PrimarySeq object
Example :
Returns : PrimarySeq object
Args    : None or PrimarySeq object

species

Title   : species
Usage   : $species = $seq->species() or $seq->species($species)
Function: Gets or sets the species
Returns : L<FAST::Bio::Species> object
Args    : None or L<FAST::Bio::Species> object

See FAST::Bio::Species for more information

Internal methods