psiblast.pl

Usage

usage:   psiblast.pl [options] [seqFile]
options:             [-nr] [-pdb] [-db name]
                     [-eshow value] [-ekeep value]
                     [-n alignments] [-i iterations]
                     [-gap initial extension]
                     [-matrix BLOSUM45|BLOSUM50|BLOSUM62|BLOSUM80|PAM250|PAM70|PAM30]
                     [-verbose] [-log file]
                     [-readlog file] [-no value]
                     [-csblast]

Show source

Description

This script calls BLAST/PSI-BLAST to find sequence alignments for the given sequence. The sequence is read from a file which should contain only the one-letter amino acid sequence either on a single or on multiple lines.

In order for this script to work, BLAST/PSI-BLAST along with recent sequence databases (nr, swissprot, pdbaa) should be installed and the BLAST utilities should be accessible through the search path.

Options

-help 

usage information

-nr 

read sequences from nr (non-redunant complete sequences) database

-pdb 

read sequences from pdbaa (sequences corresponding to PDB structures) database

-db name 

read sequences from other database (needs to be present in BLAST database location)

-eshow value 

E-value threshold for writing out alignments

-ekeep value 

E-value threshold for alignments to be used for profile generation during PSI-BLAST iteration

-n number 

maximum number of alignments to write out

-i number 

number of PSI-BLAST iterations

-gap initial extension 

gap penalties for initiation and extension

-matrix BLOSUM45|BLOSUM50|BLOSUM62|BLOSUM80|PAM250|PAM70|PAM30 

name of sequence scoring matrix

-verbose 

provide extensive output about progress

-log file 

generate log file

-readlog file 

process previously generated log file

-no number 

read alignment with given index and write out in FASTA format

Examples

psiblast.pl -pdb -log psiblast.log sequence
align the given sequence to sequences from the PDB and generate a log file with the output from PSI-BLAST

>TARGET 
RPRCFFDIAINNQPAGRVVFELFSDVCPKTCENFRCLCTGEKGTGKSTQKPLHYKSCLFHRVVKDFMVQGGDFSEGNGRGGESIYGGFFEDESFAVKHNAAFLLSMANRGKDTNGSQFFITTKPTPHLDGHHVVFGQVISGQEVVREIENQKTDAASKPFAEVRILSCGELIP
>1IHG_A ::4e-96::61::Chain A, Bovine Cyclophilin 40, Monoclinic Form
NPRVFFDVDIGGERVGRIVLELFADIVPKTAENFRALCTGEKGIGPTTGKPLHFKGCPFHRIIKKFMIQGGDFSNQNGTGGESIYGEKFEDENFHYKHDKEGLLSMANAGSNTNGSQFFITTVPTPHLDGKHVVFGQVIKGMGVAKILENVEVK-GEKPAKLCVIAECGEL..
>TARGET 
RPRCFFDIAINNQPAGRVVFELFSDVCPKTCENFRCLCTGEKGTGKSTQKPLHYKSCLFHRVVKDFMVQGGDFSEGNGRGGESIYGGFFEDESFAVKHNAAFLLSMANRGKDTNGSQFFITTKPTPHLDGHHVVFGQVISGQEVVREIENQKTDAASKPFAEVRILSCGELIP
>2RMA_A ::4e-96::52::Chain A, Crystal Structures Of Cyclophilin A Complexed With
NPTVFFDIAVDGEPLGRVSFELFADKVPKTAENFRALSTGEKGFG--------YKGSCFHRIIPGFMCQGGDFTRHNGTGGKSIYGEKFEDENFILKHTGPGILSMANAGPNTNGSQFFICTAKTEWLDGKHVVFGKVKEGMNIVEAMERFGS-RNGKTSKKITIADCGQL..
>TARGET 
RPRCFFDIAINNQPAGRVVFELFSDVCPKTCENFRCLCTGEKGTGKSTQKPLHYKSCLFHRVVKDFMVQGGDFSEGNGRGGESIYGGFFEDESFAVKHNAAFLLSMANRGKDTNGSQFFITTKPTPHLDGHHVVFGQVISGQEVVREIENQKTDAASKPFAEVRILSCGELIP

...

psiblast.pl -pdb -readlog psiblast.log -no 4 sequence
extract alignment number 4 from the log file of a previous PSI-BLAST run

>TARGET 
RPRCFFDIAINNQPAGRVVFELFSDVCPKTCENFRCLCTGEKGTGKSTQKPLHYKSCLFHRVVKDFMVQGGDFSEGNGRGGESIYGGFFEDESFAVKHNAAFLLSMANRGKDTNGSQFFITTKPTPHLDGHHVVFGQVISGQEVVREIENQKTDAASKPFAEVRILSCGELIP
>5CYH_A ::5e-96::52::Chain A, Cyclophilin A Complexed With Dipeptide Gly-Pro
NPTVFFDIAVDGEPLGRVSFELFADKVPKTAENFRALSTGEKGFG--------YKGSCFHRIIPGFMCQGGDFTRHNGTGGKSIYGEKFEDENFILKHTGPGILSMANAGPNTNGSQFFICTAKTEWLDGKHVVFGKVKEGMNIVEAMERFGS-RNGKTSKKITIADCGQL..