DELTA-BLAST : New Method to Identify Distant Homologs

I have previously discussed about guidance to select several kind of BLAST program. I have already shared the Bioinformatics video tutorial about NCBI BLAST also. If you are regular visitor of protein BLAST page then you might notice a new option beside the conventional option of blastp, PSI-BLAST, PHI-BLAST that is DELTA-BLAST (Domain Enhanced Lookup Time Accelerated BLAST). So thought lets share some basic principle ans use of  DELTA-BLAST sequence search tool in sequence analysis.
Generally, BLAST used to compare a query sequence to a database of known sequences. Position-specific-iterated BLAST (PSI-BLAST) iteratively searches a protein sequence database, using the matches in round A to construct a position-specific score matrix (PSSM) for searching the database in round A + 1 and so on. Unlike other BLAST programs, DELTA-BLAST searches a database of pre-constructed PSSMs before searching a protein-sequence database, to yield better homology detection. For its PSSMs, DELTA-BLAST employs a subset of NCBI's Conserved Domain Database (CDD).  Since DELTA-BLAST uses PSSM derived from the CDD database, so the initial PSSM construction is much more quicker than PSI-BLAST and, obviously, sensitive.

Further Readings

  1. Domain enhanced lookup time accelerated BLAST DOWNLOAD


  1. How do I perform multiple DELTA BLAST at once... like for many number of protein accession ids

    1. DELTA BLAST is not supported for multiple sequences.


Have Problem ?? Drop a comments here!