NAME

Bio::FeatureIO::ptt - read/write features in PTT format

SYNOPSIS

 # read features 
 my $fin = Bio::FeatureIO->new(-file=>'genes.ptt', -format=>'ptt');
 my @cds;
 while (my $f = $fin->next_feature) {
   push @cds, $f if $f->strand > 0;
 }
 # write features (NOT IMPLEMENTED)
 my $fout = Bio::FeatureIO->new(-fh=>\*STDOUT, -format=>'ptt');
 for my $f (@cds) {
   $fout->write_feature($f);
 }

DESCRIPTION

The PTT file format is a table of protein features. It is used mainly by NCBI who produce PTT files for all their published genomes found in <ftp://ftp.ncbi.nih.gov/genomes/>. It has the following format:

Line 1

Description of sequence to which the features belong
eg. "Leptospira interrogans chromosome II, complete sequence - 0..358943"

It is usually equivalent to the DEFINITION line of a Genbank file, with the length of the sequence appended. It is unclear why "0" is used as a starting range, it should be "1".

Line 2

Number of feature lines in the table
eg. "367 proteins"

Line 3

Column headers, tab separated
eg. "Location Strand Length PID Gene Synonym Code COG Product"

 Location : "begin..end" span of feature
 Strand   : "+" or "-"
 Length   : number of amino acids excluding the stop codon
 PID      : analogous to Genbank /db_xref="GI:xxxxxxxxx"
 Gene     : analogous to Genbank /gene="xxxx"
 Synonym  : analogous to Genbank /locus_tag="xxxx"
 Synonym  : analogous to Genbank /locus_tag="xxxx"
 COG      : CDD COG code with COG letter categories appended
 Product  : analogous to Genbank /product="xxxx"
    

Line 4 onwards

Feature lines, nine columns, tab separated, "-" used for empty fields
eg. "2491..3423 + 310 24217063 metF LB002 - COG0685E 5,10-methylenetetrahydrofolate reductase"

FEEDBACK

  bioperl-l@bioperl.org                  - General discussion
  http://bioperl.org/wiki/Mailing_lists  - About the mailing lists

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

AUTHOR - Torsten Seemann

Email torsten.seemann AT infotech.monash.edu.au

CONTRIBUTORS

Based on bed.pm and gff.pm by Allen Day.

APPENDIX

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

 Title   : _initialize
 Function: Reading? parses the header of the input
           Writing?

 Title   : next_feature
 Usage   : $io->next_feature()
 Function: read the next feature from the PTT file
 Example : 
 Args    : 
 Returns : Bio::SeqFeatureI object

 Title   : write_feature
 Usage   : $io->write_feature($feature)
 Function: write a Bio::SeqFeatureI object in PTT format
 Example : 
 Args    : Bio::SeqFeatureI object
 Returns :

 Title   : description
 Usage   : $obj->description($newval)
 Function: set/get the PTT file description for/from line one
 Example : 
 Returns : value of description (a scalar)
 Args    : on set, new value (a scalar or undef, optional)

 Title   : protein_count
 Usage   : $obj->protein_count($newval)
 Function: set/get the PTT protein count for/from line two
 Example : 
 Args    : on set, new value (a scalar or undef, optional)
 Returns : value of protein_count (a scalar)