[Bioperl-l] tblastn, retrieving no match Aa from subject string
Anders Stegmann
anst at kvl.dk
Tue Dec 27 17:15:52 EST 2005
Hi!
I am blasting a protein seq against a chromosome by using tblastn in a bioperl script.
my protein seq is 1250 Aa corresponding to 3750 nt.
by doing:
$hsp->start('hit') I get 1045637
$hsp->end('hit') I get 1049386
which is okay.
by doing:
foreach ($hsp_obj->seq_inds('query', 'nomatch')) {
print $_, "\n";
}
I get 2, which okay because I made a Aa substitution in the query seq at position two.
but when I go:
foreach ($hsp_obj->seq_inds('hit', 'nomatch')) {
print $_, "\n";
}
I get 349793 which I can't explain.
what is this number telling me?
According to the Bio::SearchIO HOWTO I should get the position of the not matching Aa the subject DNA seq. I guess that because I am using tblastn I get the position of a nucleotide in the codon of the not matching Aa, but that doesn't correspond to start and end positions written above.
The easiest way out of this would be if I somehow could retrieve the not matching Aa position from the translated protein hit string. As I can when two proteins are blasted agsinst each other.
does anybody know how?
(note: as the script works when two proteins are blasted against each other the code should be okay)
Regards Anders.
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