bioperl Bio::SeqIO join + complement weirdness

Question

[Stephane Plaisance]

I used a simplistic script to convert GB to EMBL format and manual inspection reveals strange behaviour

#!/usr/bin/perl -w
use strict;
use Bio::SeqIO;

if (@ARGV != 2) { die "USAGE: gb2embl.pl <GB_file> <EMBL_name>\n"; }

my $seqio = Bio::SeqIO->new('-format' => 'genbank', '-file' => "$ARGV[0]");
my $seqout = new Bio::SeqIO('-format' => 'embl', '-file' => ">$ARGV[1]");
while( my $seq = $seqio->next_seq) {
  $seqout->write_seq($seq)
}

a piece of input GB formatted

 mRNA            complement(join(280..5840,5989..6007))
                 /gene="YRF1-7"
                 /locus_tag="YPL283C"
                 /gene_synonym="YRF1"
                 /product="Y' element ATP-dependent helicase protein 1 copy
                 7"

the same piece in the embl output

FT   mRNA            join(complement(280..5840),complement(5989..6007))
FT                   /locus_tag="YPL283C"
FT                   /gene_synonym="YRF1"
FT                   /gene="YRF1-7"
FT                   /product="Y' element ATP-dependent helicase protein 1 copy
FT                   7"

I do not think that this is OK

complement( join ( -1-> -2-> ) ) = <-2- <-1-
join( complement( -1-> ) complement ( -2-> ) ) = <-1- <-2-

the order gets inverted by this logic, leading to chaotic sequence fusion

Anybody agrees and/or has comments?

Bioperl used: 1.007001

[Stephane Plaisance]

you have a point, I did not consider this. thanks for your clarification!

[WouterDeCoster]

Hi Stephane,

Please use ADD COMMENT to reply to earlier answers, as such this thread remains logically structured and easy to follow. Thanks!

Cheers,
Wouter

Answer 1

[Michael]

Why do you think that the order gets inverted? It says _complement_ not _reverse complement_. If it was reverse complement, you would be right.

compl( ACCG ) + compl( TTAA) = UGGC + AAUU = UGGC AAUU = compl (ACCG TTAA) = compl (ACCG + TTAA)

It seems as if the mRNA splice string is processed somehow by bioperl, but it would be interesting to check a reverse strand gene also.