Provided by: libbio-perl-perl_1.7.2-2_all 
NAME
Bio::SeqIO::swiss - Swissprot sequence input/output stream
SYNOPSIS
It is probably best not to use this object directly, but rather go through the SeqIO
handler system:
use Bio::SeqIO;
$stream = Bio::SeqIO->new(-file => $filename,
-format => 'swiss');
while ( my $seq = $stream->next_seq() ) {
# do something with $seq
}
DESCRIPTION
This object can transform Bio::Seq objects to and from Swiss-Pprot flat file databases.
There is a lot of flexibility here about how to dump things which needs to be documented.
GN (Gene name) line management details
A Uniprot/Swiss-Prot entry holds information on one protein sequence. If that sequence is
identical across genes and species, they are all merged into one entry. This creates
complex needs for several annotation fields in swiss-prot format.
The latest syntax for GN line is described in the user manual:
http://www.expasy.ch/sprot/userman.html#GN_line
Each of the possibly multiple genes in an entry can have Name, Synonyms (only if there is
a name), OrderedLocusNames (names from genomic sequences) and ORFNames (temporary or
cosmid names). "Name" here really means "symbol". This complexity is now dealt with the
following way:
A new Bio::AnnotationI class was created in order to store the data in tag-value pairs.
This class (Bio::Annotation::TagTree) is stored in the Bio::Annotation::Collection object
and is accessed like all other annotations. The tag name is 'gene_name'.
There is a single Bio::Annotation::TagTree per sequence record, which corresponds to the
original class that stored this data (Bio::Annotation::StructuredValue). Depending on how
we progress this may change to represent each group of gene names.
For now, to access the gene name tree annotation, one uses the below method:
my ($gene) = $seq->annotation->get_Annotations('gene_name');
If you are only interested in displaying the values, value() returns a string with similar
formatting.
There are several ways to get directly at the information you want if you know the element
(tag) for the data. For gene names all data is stored with the element-tag pairs:
"element1=tag1, tag2, tag3; element2=tag4, tag5;"
This normally means the element will be 'Name', 'Synonyms', etc. and the gene names the
values. Using findval(), you can do the following:
# grab a flattened list of all gene names
my @names = $ann->findval('Name');
# or iterated through the nodes and grab the name for each group
for my $node ($ann->findnode('gene_name')) {
my @names = $node->findval('Name');
}
The current method for parsing gene name data (and reconstructing gene name output) is
very generic. This is somewhat preemptive if, for instance, UniProt decides to update and
add another element name to the current ones using the same formatting layout. Under those
circumstances, one can iterate through the tag tree in a safe way and retrieve all node
data like so.
# retrieve the gene name nodes (groups like names, synonyms, etc).
for my $ann ($seq->annotation->get_Annotations('gene_name')) {
# each gene name group
for my $node ($ann->findnode('gene_name')) {
print "Gene name:\n";
# each gene name node (tag => value pair)
for my $n ($node->children) {
print "\t".$n->element.": ".$n->children."\n";
}
}
}
For more uses see Bio::Annotation::TagTree.
Since Uniprot/Swiss-Prot format have been around for quite some time, the parser is also
able to read in the older GN line syntax where genes are separated by AND and various
symbols by OR. The first symbol is taken to be the 'Name' and the remaining ones are
stored as 'Synonyms'.
Also, for UniProt output we support using other Bio::AnnotationI, but in this case we only
use the stringified version of the annotation. This is to allow for backwards
compatibility with code that previously used Bio::Annotation::SimpleValue or other
Bio::AnnotationI classes.
Optional functions
_show_dna()
(output only) shows the dna or not
_post_sort()
(output only) provides a sorting func which is applied to the FTHelpers before printing
_id_generation_func()
This is function which is called as
print "ID ", $func($seq), "\n";
To generate the ID line. If it is not there, it generates a sensible ID line using a
number of tools.
If you want to output annotations in Swissprot format they need to be stored in a
Bio::Annotation::Collection object which is accessible through the Bio::SeqI interface
method annotation().
The following are the names of the keys which are polled from a
Bio::Annotation::Collection object.
reference - Should contain Bio::Annotation::Reference objects
comment - Should contain Bio::Annotation::Comment objects
dblink - Should contain Bio::Annotation::DBLink objects
gene_name - Should contain Bio::Annotation::SimpleValue object
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://github.com/bioperl/bioperl-live/issues
AUTHOR - Elia Stupka
Email elia@tll.org.sg
APPENDIX
The rest of the documentation details each of the object methods. Internal methods are
usually preceded with a _
next_seq
Title : next_seq
Usage : $seq = $stream->next_seq()
Function: returns the next sequence in the stream
Returns : Bio::Seq object
Args :
write_seq
Title : write_seq
Usage : $stream->write_seq($seq)
Function: writes the $seq object (must be seq) to the stream
Returns : 1 for success and 0 for error
Args : array of 1 to n Bio::SeqI objects
_generateCRCTable
Title : _generateCRCTable
Usage :
Function:
Example :
Returns :
Args :
_crc32
Title : _crc32
Usage :
Function:
Example :
Returns :
Args :
_crc64
Title : _crc64
Usage :
Function:
Example :
Returns :
Args :
_print_swissprot_FTHelper
Title : _print_swissprot_FTHelper
Usage :
Function:
Example :
Returns :
Args :
_read_swissprot_References
Title : _read_swissprot_References
Usage :
Function: Reads references from swissprot format. Internal function really
Example :
Returns :
Args :
_read_swissprot_Species
Title : _read_swissprot_Species
Usage :
Function: Reads the swissprot Organism species and classification
lines.
Able to deal with unconventional species names.
Example : OS Unknown prokaryotic organism
$genus = undef ; $species = Unknown prokaryotic organism
Returns : A Bio::Species object
Args :
_filehandle
Title : _filehandle
Usage : $obj->_filehandle($newval)
Function:
Example :
Returns : value of _filehandle
Args : newvalue (optional)
_read_FTHelper_swissprot
Title : _read_FTHelper_swissprot
Usage : _read_FTHelper_swissprot(\$buffer)
Function: reads the next FT key line
Example :
Returns : Bio::SeqIO::FTHelper object
Args :
_write_line_swissprot
Title : _write_line_swissprot
Usage :
Function: internal function
Example :
Returns :
Args :
_write_line_swissprot_regex
Title : _write_line_swissprot_regex
Usage :
Function: internal function for writing lines of specified
length, with different first and the next line
left hand headers and split at specific points in the
text
Example :
Returns : nothing
Args : file handle, first header, second header, text-line, regex for line breaks, total line length
_post_sort
Title : _post_sort
Usage : $obj->_post_sort($newval)
Function:
Returns : value of _post_sort
Args : newvalue (optional)
_show_dna
Title : _show_dna
Usage : $obj->_show_dna($newval)
Function:
Returns : value of _show_dna
Args : newvalue (optional)
_id_generation_func
Title : _id_generation_func
Usage : $obj->_id_generation_func($newval)
Function:
Returns : value of _id_generation_func
Args : newvalue (optional)
_ac_generation_func
Title : _ac_generation_func
Usage : $obj->_ac_generation_func($newval)
Function:
Returns : value of _ac_generation_func
Args : newvalue (optional)
_sv_generation_func
Title : _sv_generation_func
Usage : $obj->_sv_generation_func($newval)
Function:
Returns : value of _sv_generation_func
Args : newvalue (optional)
_kw_generation_func
Title : _kw_generation_func
Usage : $obj->_kw_generation_func($newval)
Function:
Returns : value of _kw_generation_func
Args : newvalue (optional)