BLAST+ Command Line Applications The NCBI Basic Local Alignment Search Tool (BLAST) finds regions of local similarity between sequences. The program compares nucleotide or protein sequences to sequence databases and calculates the statistical significance of matches. BLAST can be used to infer functional and evolutionary relationships between sequences as well as help identify members of gene families. The Basic Local Alignment Search Tool (BLAST) is the most widely used sequence similarity tool. There are versions of BLAST that compare protein queries to protein databases, nucleotide queries to nucleotide databases, as well as versions that translate nucleotide queries or databases in all six frames and compare to protein databases or queries. PSI-BLAST produces a position-specific-scoring-matrix (PSSM) starting with a protein query, and then uses that PSSM to perform further searches. It is also possible to compare a protein or nucleotide query to a database of PSSM’s. The NCBI supports a BLAST web page (at blast.ncbi.nlm.nih.gov) as well as a network service. The NCBI also distributes stand-alone BLAST applications for users who wish to run BLAST on their own machines or with their own databases. BLAST+ is a new suite of BLAST tools that utilizes the NCBI C++ Toolkit. The BLAST+ applications have a number of performance and feature improvements over the legacy BLAST applications (ncbi-blast). Some useful links: Help https://www.ncbi.nlm.nih.gov/books/NBK1762/ Manual https://www.ncbi.nlm.nih.gov/books/NBK279690/ Downloads ftp://ftp.ncbi.nih.gov/blast/executables/blast+/ Databases ftp://ftp.ncbi.nlm.nih.gov/blast/db/ ChangeLog http://www.ncbi.nlm.nih.gov/books/NBK131777 Reference https://www.ncbi.nlm.nih.gov/pubmed/20003500 Citing: BLAST+: architecture and applications. Camacho C, Coulouris G, Avagyan V, Ma N, Papadopoulos J, Bealer K, Madden TL. BMC Bioinformatics. 2009 Dec 15;10:421. doi: 10.1186/1471-2105-10-421.