How to dissolve blastn alignment result predicted locally

Question

[Neu]

Hi, I have predicted RNA-RNA interaction using blastn locally with the option strand=both. How can I dissolve the output file (as described below) to get RNA pairs with specifications: strand plus/minus, 95% identity and minimum length 25. (I do have a result in tabular format obtained by using outfmt 6, but that does not have both stand information.)

Query= chr1:1080738-1080845

Length=107

Sequences producing significant alignments:       Score     E                   (Bits)  Value

ENST00000367311.4     36.2    0.22  
ENST00000368686.1     34.4    0.79  
ENST00000397906.6    32.5    2.8  
ENST00000612946.4    32.5    2.8  
ENST00000614107.4   32.5    2.8  
ENST00000304166.8    32.5    2.8  


>ENST00000367311.4 
Length=2640

 Score = 36.2 bits (19),  Expect = 0.22
 Identities = 22/23 (96%), Gaps = 1/23 (4%)
 Strand=Plus/Plus

Query  56    TCGGCCATGAAGGTGGTGGGGGT  78
             |||||| ||||||||||||||||
Sbjct  1435  TCGGCC-TGAAGGTGGTGGGGGT  1456


>ENST00000368686.1 
Length=2250

 Score = 34.4 bits (18),  Expect = 0.79
 Identities = 18/18 (100%), Gaps = 0/18 (0%)
 Strand=Plus/Minus

[i.sudbery]

Hi @Neu, its not clear what you mean by the word "dissolve". Do you mean parse? Or filter?

Answer 1

[i.sudbery]

Depending on what lanuage you preffer you might like to check out the Biopython blast results parser (see introduction here). I guess bioperl, biojava probably have similar tools. R has something called rBLAST, but I've never used it.