Bio::LiveSeq::SeqI.3pm

Langue: en

Version: 2010-05-19 (ubuntu - 24/10/10)

Section: 3 (Bibliothèques de fonctions)

NAME

Bio::LiveSeq::SeqI - Abstract sequence interface class for LiveSeq

SYNOPSIS

   # documentation needed
 
 

DESCRIPTION

This class implements BioPerl PrimarySeqI interface for Live Seq objects.

One of the main difference in LiveSequence compared to traditional ``string'' sequences is that coordinate systems are flexible. Typically gene nucleotide numbering starts from 1 at the first character of the initiator codon (A in ATG). This means that negative positions are possible and common!

Secondly, the sequence manipulation methods do not return a new sequence object but change the current object. The current status can be written out to BioPerl sequence objects.

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:
   http://bugzilla.open-bio.org/
 
 

AUTHOR - Joseph A.L. Insana

Email: Insana@ebi.ac.uk, jinsana@gmx.net

APPENDIX

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

Some note on the terminology/notation of method names:
 label: a unique pointer to a single nucleotide
 position: the position of a nucleotide according to a particular coordinate
           system (e.g. counting downstream from a particular label taken as
           number 1)
 base: the one letter code for a nucleotide (i.e.: ``a'' ``t'' ``c'' ``g'')

        a base is the "value" that an "element" of a "chain" can assume
          (see documentation on the Chain datastructure if interested)
 
 

seq

  Title   : seq
  Usage   : $string    = $obj->seq()
  Function: Returns the complete sequence of an object as a string of letters.
            Suggested cases are upper case for proteins and lower case for
            DNA sequence (IUPAC standard),
  Returns : a string
 
 

all_labels

  Title   : all_labels
  Usage   : @labels = $obj->all_labels()
  Function: all the labels of every nucleotide an object is composed of
  Returns : an array of labels
  Args    : none
 
 

labelsubseq

   Title   : labelsubseq
   Usage   : $dna->labelsubseq();
           : $dna->labelsubseq($startlabel);
           : $dna->labelsubseq($startlabel,$length);
           : $dna->labelsubseq($startlabel,undef,$endlabel);
   e.g.    : $dna->labelsubseq(4,undef,8);
   Function: prints the sequence as string. The difference between labelsubseq
             and normal subseq is that it uses /labels/ as arguments, instead
             than positions. This allows for faster and more efficient lookup,
             skipping the (usually) lengthy conversion of positions into labels.
             This is expecially useful for manipulating with high power
             LiveSeq objects, knowing the labels and exploiting their
             usefulness.
   Returns : a string
   Errorcode -1
   Args    : without arguments it returns the entire sequence
             with a startlabel it returns the sequence downstream that label
             if a length is specified, it returns only that number of bases
             if an endlabel is specified, it overrides the length argument
              and prints instead up to that label (included)
   Defaults: $startlabel defaults to the beginning of the entire sequence
             $endlabel defaults to the end of the entire sequence
 
 

subseq

  Title   : subseq
  Usage   : $substring = $obj->subseq(10,40);
          : $substring = $obj->subseq(10,undef,4);
  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.
 
            Allows for negative numbers $obj->subseq(-10,-1). By
            definition, there is no 0!
                        -5  -1 1   5
                 gctagcgcccaac atggctcgctg
 
            This allows to retrieve sequences upstream from given position.
 
            The precedence is from left to right: if END is given LENGTH is
            ignored.
 
  Examples: $obj->subseq(-10,undef,10) returns 10 elements before position 1
            $obj->subseq(4,8) returns elements from the 4th to the 8th, inclusive
 
  Returns : a string
  Errorcode: -1
  Args    : start,  integer, defaults to start of the sequence
            end,    integer, '' or undef, defaults to end of the sequence
            length, integer, '' or undef
            an optional strand (1 or -1) 4th argument 
             if strand argument is not given, it will default to the object
             argment. This argument is useful when a call is issued from a child
             of a parent object containing the subseq method
 
 

length

   Title   : length
   Usage   : $seq->length();
   Function: returns the number of nucleotides (or the number of aminoacids)
             in the entire sequence
   Returns : an integer
   Errorcode -1
   Args    : none
 
 

display_id

  Title   : display_id
  Usage   : $id_string = $obj->display_id();
  Function: returns the display id, alias the common name of the 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 ID
            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.
 
  See also: accession_number
  Returns : a string
  Args    : none
 
 

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.
            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 objects with no accession_number this method returns "unknown".
  Returns : a string
  Args    : 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 primary_id, this method returns
            a stringified memory location.
 
  Returns : A string
  Args    : None
 
 

change

  Title   : change
  Usage   : $substring = $obj->change('AA', 10);
  Function: changes, modifies, mutates the LiveSequence
  Examples:
         $obj->change('',   10);      delete nucleotide #10     
         $obj->change('',   10, 2);   delete two nucleotides starting from #10
         $obj->change('G',  10);      change nuc #10 to 'G'
         $obj->change('GA', 10, 4);   replace #10 and 3 following with 'GA'
         $obj->change('GA', 10, 2));  is same as $obj->change('GA',  10);
         $obj->change('GA', 10, 0 );  insert 'GA' before nucleotide at #10
         $obj->change('GA', 10, 1);   GA inserted before #10, #10 deleted
         $obj->change('GATC', 10, 2); GATC inserted before #10, #10&#11 deleted
         $obj->change('GATC', 10, 6); GATC inserted before #10, #10-#15 deleted
 
 
  Returns : a string of deleted bases (if any) or 1 (everything OK)
  Errorcode: -1
  Args    : seq,    string, or '' ('' = undef = 0 = deletion)
            start,  integer
            length, integer (optional)
 
 

positionchange

  Title   : positionchange
  Function: Exactly like change. I.e. change() defaults to positionchange()
 
 

labelchange

  Title   : labelchange
  Function: Exactly like change but uses a /label/ instead than a position
            as second argument. This allows for multiple changes in a LiveSeq
            without the burden of recomputing positions. I.e. for a multiple
            change in two different points of the LiveSeq, the approach would
            be the following: fetch the correct labels out of the two different
            positions (method: label($position)) and then use the labelchange()
            method to modify the sequence using those labels instead than
            relying on the positions (that would have modified after the
            first change).
 
 

valid

   Title   : valid
   Usage   : $boolean = $obj->valid($label)
   Function: tests if a label exists inside the object
   Returns : boolean
   Args    : label
 
 

start

   Title   : start
   Usage   : $startlabel=$obj->start()
   Function: returns the label of the first nucleotide of the object (exon, CDS)
   Returns : label
   Args    : none
 
 

end

   Title   : end
   Usage   : $endlabel=$obj->end()
   Function: returns the label of the last nucleotide of the object (exon, CDS)
   Returns : label
   Args    : none
 
 

strand

   Title   : strand
   Usage   : $strand=$obj->strand()
             $obj->strand($strand)
   Function: gets or sets strand information, being 1 or -1 (forward or reverse)
   Returns : -1 or 1
   Args    : none OR -1 or 1
 
 

alphabet

  Title   : alphabet
  Usage   : if( $obj->alphabet eq 'dna' ) { /Do Something/ }
  Function: Returns the type of sequence being one of
            'dna', 'rna' or 'protein'. This is case sensitive.
 
  Returns : a string either 'dna','rna','protein'.
  Args    : none
 
 

coordinate_start

   Title   : coordinate_start
   Usage   : $coordstartlabel=$obj->coordinate_start()
           : $coordstartlabel=$obj->coordinate_start($label)
   Function: returns and optionally sets the first label of the coordinate
             system used
             For some objects only labels inside the object or in frame (for
             Translation objects) will be allowed to get set as coordinate start
 
   Returns : label. It returns 0 if label not found.
   Errorcode -1 
   Args    : an optional reference $label that is position 1
 
 

label

   Title   : label
   Usage   : $seq->label($position)
           : $seq->label($position,$firstlabel)
   Examples: $nextlabel=$seq->label(2,$label) -> retrieves the following label
           : $prevlabel=$seq->label(-1,$label) -> retrieves the preceding label
 
   Function: returns the label of the nucleotide at $position from current
             coordinate start
   Returns : a label. It returns 0 if label not found.
   Errorcode -1 
   Args    : a position, 
             an optional reference $firstlabel that is to be used as position 1
             an optional strand (1 or -1) argument 
              if strand argument is not given, it will default to the object
              argument. This argument is useful when a call is issued from a child
              of a parent object containing the subseq method
 
 

position

   Title   : position
   Usage   : $seq->position($label)
           : $seq->position($label,$firstlabel)
   Function: returns the position of nucleotide at $label
   Returns : the position of the label from current coordinate start
   Errorcode 0
   Args    : a label pointing to a certain nucleotide (e.g. start of exon)
             an optional "firstlabel" as reference to count from
             an optional strand (1 or -1) argument 
              if strand argument is not given, it will default to the object
              argument. This argument is useful when a call is issued from a child
              of a parent object containing the subseq method
 
 

follows

   Title   : follows
   Usage   : $seq->follows($firstlabel,$secondlabel)
           : $seq->follows($firstlabel,$secondlabel,$strand)
   Function: checks if SECONDlabel follows FIRSTlabel, undependent of the strand
             i.e. it checks downstream for forward strand and
             upstream for reverse strand
   Returns : 1 or 0
   Errorcode -1
   Args    : two labels
             an optional strand (1 or -1) argument 
              if strand argument is not given, it will default to the object
              argument. This argument is useful when a call is issued from a child
              of a parent object containing the subseq method
 
 

gene

  Title   : gene
  Usage   : my $gene=$obj->gene;
  Function: Gets or sets the reference to the LiveSeq::Gene object.
            Objects that are features of a LiveSeq Gene will have this
            attribute set automatically.
 
  Returns : reference to an object of class Gene
  Note    : if Gene object is not set, this method will return 0;
  Args    : none or reference to object of class Bio::LiveSeq::Gene
 
 

obj_valid

  Title   : obj_valid
  Usage   : if ($obj->obj_valid) {do something;}
  Function: Checks if start and end labels are still valid for the ojbect,
            i.e. tests if the LiveSeq object is still valid
  Returns : boolean
  Args    : none
 
 

name

  Title   : name
  Usage   : $name = $obj->name;
          : $name = $obj->name("ABCD");
  Function: Returns or sets the name of the object.
            If there is no name, it will return "unknown";
  Returns : A string
  Args    : None
 
 

desc

  Title   : desc
  Usage   : $desc = $obj->desc;
          : $desc = $obj->desc("ABCD");
  Function: Returns or sets the description of the object.
            If there is no description, it will return "unknown";
  Returns : A string
  Args    : None
 
 

source

  Title   : source
  Usage   : $name = $obj->source;
          : $name = $obj->source("Homo sapiens");
  Function: Returns or sets the organism that is source of the object.
            If there is no source, it will return "unknown";
  Returns : A string
  Args    : None