Blast Error: Tax database file not found

Question

[navillusol858]

Hello, I am running this command for a blast search.

blastx -query Ndiv_cap300.fasta -out Ndiv_run -outfmt 7 -db nr -num_threads 32 -evalue 1e-3 -max_target_seqs 5

however I get the following error that I just do not understand

/Liams_Work$ blastx -query Ndiv_cap300.fasta -out Ndiv_run -outfmt 7 -db nr -num_threads 32 -evalue 1e-3 -max_target_seqs 5
terminate called after throwing an instance of 'ncbi::CSeqDBException'
  what():  NCBI C++ Exception:
    "/build/buildd/ncbi-blast+-2.2.28/c++/src/objtools/blast/seqdb_reader/seqdbtax.cpp", line 82: Error: ncbi::CSeqDBTaxInfo::x_Init() - Error: Tax database file not found.

any help would be greatly appreciated.

Thanks in advance!

Answer 1

[hpmcwill]

That error message suggests that NCBI BLAST+ is attempting to look-up taxonomy information and is failing due to the Taxonomy database not being present in the directory containing the database being searched.

In order to allow NCBI BLAST+ to access the taxonomy information you will need to download 'taxdb.tar.gz' from ftp://ftp.ncbi.nlm.nih.gov/blast/db/ and unpack it into the same directory as you are using for the 'nr' database. For more information about the BLAST databases provided by NCBI see ftp://ftp.ncbi.nlm.nih.gov/blast/db/README and the various database related sections of the BLAST Command Line Applications User Manual.

[5heikki]

Except that his query should not require taxdb. It looks to me (I could be wrong), that OP has, instead of using a binary, compiled blast from the source himself, and that the root of the problem lies there.

[navillusol858]

hpmcwill your solution worked thank you very much.