Wikiomics:PSI-BLAST

PSI-BLAST - Position-Specific Iterated BLAST. Variant of BLAST used for disovery of weak but relevant protein sequence matches. The algorithm is based on running consequitive BLAST searches using position weight matices:


 * query sequence ->
 * first blast search ->
 * first iteration blast results ->
 * sequence alignment of strong matches ->
 * creating a profile #1 ->
 * second iteration blast search with profile #1 as a query ->
 * second iteration blast results, etc.

PSI-BLAST server at NCBI: link

Tutorials

 * @NCBI Part 1
 * @NCBI Part 2
 * @NCBI Part 3
 * @Uni-Saaraland (DOC)]