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Web Blast Server
The 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. - from NCBI
- Regular BLAST
includes five programs:
blastn - nucleotide sequence against
nucleotide database;
blastp - amino acid sequence against
protein database;
blastx - nucleotide (six-frame
translation)
sequence against protein database;
tblastn - protein sequence against
nucleotide database (dynamically
translated in all six reading frames).
tblastx - nucleotide (six-frame translation)
sequence against
nucleotide database
(six-frame translations).
- PSI/PHI BLAST
Position Specific Iterated and Pattern
Hit Initiated BLAST
is constructed (automatically) from a multiple alignment of the
highest scoring hits in an initial BLAST search. The PSSM is generated
by calculating position-specific scores for each position in the
alignment. Highly conserved positions receive high scores and weakly
conserved positions receive scores near zero. The profile is used to
perform a second (etc.) BLAST search and the results of each
"iteration" used to refine the profile. This iterative searching
strategy results in increased sensitivity. Visit NCBI
for details.
- Mega BLAST
Mega BLAST uses a greedy algorithm for the nucleotide sequence
alignment search. This program is optimized for aligning sequences
that differ slightly as a result of sequencing or other similar
"errors". When larger word size is used, it is
up to 10 times faster than more common sequence similarity
programs. Mega BLAST is also able to efficiently handle much longer
DNA sequences than the blastn program of traditional BLAST algorithm.
Visit
NCBI for details.
- BLAST 2 sequences
This tool produces the alignment of two given sequences using
BLAST engine for local alignment.
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