Bio::DB::GenBank.3pm

Langue: en

Autres versions - même langue

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

Section: 3 (Bibliothèques de fonctions)

Sommaire

NAME

Bio::DB::GenBank - Database object interface to GenBank

SYNOPSIS

     use Bio::DB::GenBank;
     $gb = Bio::DB::GenBank->new();
 
     $seq = $gb->get_Seq_by_id('MUSIGHBA1'); # Unique ID
 
     # or ...
 
     $seq = $gb->get_Seq_by_acc('J00522'); # Accession Number
     $seq = $gb->get_Seq_by_version('J00522.1'); # Accession.version
     $seq = $gb->get_Seq_by_gi('405830'); # GI Number
 
     # get a stream via a query string
     my $query = Bio::DB::Query::GenBank->new
         (-query   =>'Oryza sativa[Organism] AND EST',
          -reldate => '30',
          -db      => 'nucleotide');
     my $seqio = $gb->get_Stream_by_query($query);
 
     while( my $seq =  $seqio->next_seq ) {
       print "seq length is ", $seq->length,"\n";
     }
 
     # or ... best when downloading very large files, prevents
     # keeping all of the file in memory
 
     # also don't want features, just sequence so let's save bandwith
     # and request Fasta sequence
     $gb = Bio::DB::GenBank->new(-retrievaltype => 'tempfile' , 
                                               -format => 'Fasta');
     my $seqio = $gb->get_Stream_by_acc(['AC013798', 'AC021953'] );
     while( my $clone =  $seqio->next_seq ) {
       print "cloneid is ", $clone->display_id, " ", 
              $clone->accession_number, "\n";
     }
     # note that get_Stream_by_version is not implemented
 
     # don't want the entire sequence or more options
     my $gb = Bio::DB::GenBank->new(-format     => 'Fasta',
                                    -seq_start  => 100,
                                    -seq_stop   => 200,
                                    -strand     => 1,
                                    -complexity => 4);
     my $seqi = $gb->get_Stream_by_query($query);

DESCRIPTION

Allows the dynamic retrieval of Bio::Seq sequence objects from the GenBank database at NCBI, via an Entrez query.

WARNING: Please do NOT spam the Entrez web server with multiple requests. NCBI offers Batch Entrez for this purpose.

Note that when querying for GenBank accessions starting with 'NT_' you will need to call $gb->request_format('fasta') beforehand, because in GenBank format (the default) the sequence part will be left out (the reason is that NT contigs are rather annotation with references to clones).

Some work has been done to automatically detect and retrieve whole NT_ clones when the data is in that format (NCBI RefSeq clones). The former behavior prior to bioperl 1.6 was to retrieve these from EBI, but now these are retrieved directly from NCBI. The older behavior can be regained by setting the 'redirect_refseq' flag to a value evaluating to TRUE.

Running

Alternate methods are described at <http://www.ncbi.nlm.nih.gov/entrez/query/static/efetchseq_help.html>

NOTE: strand should be 1 for plus or 2 for minus.

Complexity: gi is often a part of a biological blob, containing other gis

complexity regulates the display:
  0 - get the whole blob
  1 - get the bioseq for gi of interest (default in Entrez)
  2 - get the minimal bioseq-set containing the gi of interest
  3 - get the minimal nuc-prot containing the gi of interest
  4 - get the minimal pub-set containing the gi of interest

'seq_start' and 'seq_stop' will not work when setting complexity to any value other than 1. 'strand' works for any setting other than a complexity of 0 (whole glob); when you try this with a GenBank return format nothing happens, whereas using FASTA works but causes display problems with the other sequences in the glob. As Tao Tao says from NCBI, ``Better left it out or set it to 1.''

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 - Aaron Mackey, Jason Stajich

Email amackey@virginia.edu Email jason@bioperl.org

APPENDIX

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

new

  Title   : new
  Usage   : $gb = Bio::DB::GenBank->new(@options)
  Function: Creates a new genbank handle
  Returns : New genbank handle
  Args    : -delay   number of seconds to delay between fetches (3s)

NOTE: There are other options that are used internally. By NCBI policy, this module introduces a 3s delay between fetches. If you are fetching multiple genbank ids, it is a good idea to use get

get_params

  Title   : get_params
  Usage   : my %params = $self->get_params($mode)
  Function: Returns key,value pairs to be passed to NCBI database
            for either 'batch' or 'single' sequence retrieval method
  Returns : a key,value pair hash
  Args    : 'single' or 'batch' mode for retrieval

Routines Bio::DB::WebDBSeqI from Bio::DB::RandomAccessI

get_Seq_by_id

  Title   : get_Seq_by_id
  Usage   : $seq = $db->get_Seq_by_id('ROA1_HUMAN')
  Function: Gets a Bio::Seq object by its name
  Returns : a Bio::Seq object
  Args    : the id (as a string) of a sequence
  Throws  : "id does not exist" exception

get_Seq_by_acc

   Title   : get_Seq_by_acc
   Usage   : $seq = $db->get_Seq_by_acc($acc);
   Function: Gets a Seq object by accession numbers
   Returns : a Bio::Seq object
   Args    : the accession number as a string
   Note    : For GenBank, this just calls the same code for get_Seq_by_id().
             Caveat: this normally works, but in rare cases simply passing the
             accession can lead to odd results, possibly due to unsynchronized
             NCBI ID servers. Using get_Seq_by_version() is slightly better, but
             using the unique identifier (GI) and get_Seq_by_id is the most
             consistent
   Throws  : "id does not exist" exception

get_Seq_by_gi

  Title   : get_Seq_by_gi
  Usage   : $seq = $db->get_Seq_by_gi('405830');
  Function: Gets a Bio::Seq object by gi number
  Returns : A Bio::Seq object
  Args    : gi number (as a string)
  Throws  : "gi does not exist" exception

get_Seq_by_version

  Title   : get_Seq_by_version
  Usage   : $seq = $db->get_Seq_by_version('X77802.1');
  Function: Gets a Bio::Seq object by sequence version
  Returns : A Bio::Seq object
  Args    : accession.version (as a string)
  Note    : Caveat: this normally works, but using the unique identifier (GI) and
            get_Seq_by_id is the most consistent
  Throws  : "acc.version does not exist" exception

Routines implemented by Bio::DB::NCBIHelper

get_Stream_by_query

   Title   : get_Stream_by_query
   Usage   : $seq = $db->get_Stream_by_query($query);
   Function: Retrieves Seq objects from Entrez 'en masse', rather than one
             at a time.  For large numbers of sequences, this is far superior
             than get_Stream_by_[id/acc]().
   Example :
   Returns : a Bio::SeqIO stream object
   Args    : $query :   An Entrez query string or a
             Bio::DB::Query::GenBank object.  It is suggested that you
             create a Bio::DB::Query::GenBank object and get the entry
             count before you fetch a potentially large stream.

get_Stream_by_id

   Title   : get_Stream_by_id
   Usage   : $stream = $db->get_Stream_by_id( [$uid1, $uid2] );
   Function: Gets a series of Seq objects by unique identifiers
   Returns : a Bio::SeqIO stream object
   Args    : $ref : a reference to an array of unique identifiers for
                    the desired sequence entries

get_Stream_by_acc

   Title   : get_Stream_by_acc
   Usage   : $seq = $db->get_Stream_by_acc([$acc1, $acc2]);
   Function: Gets a series of Seq objects by accession numbers
   Returns : a Bio::SeqIO stream object
   Args    : $ref : a reference to an array of accession numbers for
                    the desired sequence entries
   Note    : For GenBank, this just calls the same code for get_Stream_by_id()

get_Stream_by_gi

   Title   : get_Stream_by_gi
   Usage   : $seq = $db->get_Seq_by_gi([$gi1, $gi2]);
   Function: Gets a series of Seq objects by gi numbers
   Returns : a Bio::SeqIO stream object
   Args    : $ref : a reference to an array of gi numbers for
                    the desired sequence entries
   Note    : For GenBank, this just calls the same code for get_Stream_by_id()

get_Stream_by_batch

   Title   : get_Stream_by_batch
   Usage   : $seq = $db->get_Stream_by_batch($ref);
   Function: Retrieves Seq objects from Entrez 'en masse', rather than one
             at a time.
   Example :
   Returns : a Bio::SeqIO stream object
   Args    : $ref : either an array reference, a filename, or a filehandle
             from which to get the list of unique ids/accession numbers.

NOTE: This method is redundant and deprecated. Use get_Stream_by_id() instead.

get_request

  Title   : get_request
  Usage   : my $url = $self->get_request
  Function: HTTP::Request
  Returns : 
  Args    : %qualifiers = a hash of qualifiers (ids, format, etc)

default_format

  Title   : default_format
  Usage   : my $format = $self->default_format
  Function: Returns default sequence format for this module
  Returns : string
  Args    : none