Cited by 73,302Genomics and Phylogenetic StudiesAlgorithms and Data CompressionFractal and DNA sequence analysis

Gapped BLAST and PSI-BLAST: a new generation of protein database search programs

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Altschul, S.·1997·Nucleic Acids Research

Abstract

The BLAST programs are widely used tools for searching protein and DNA databases for sequence similarities. For protein comparisons, a variety of definitional, algorithmic and statistical refinements described here permits the execution time of the BLAST programs to be decreased substantially while enhancing their sensitivity to weak similarities. A new criterion for triggering the extension of word hits, combined with a new heuristic for generating gapped alignments, yields a gapped BLAST program that runs at approximately three times the speed of the original. In addition, a method is introduced for automatically combining statistically significant alignments produced by BLAST into a position-specific score matrix, and searching the database using this matrix. The resulting Position-Specific Iterated BLAST (PSI-BLAST) program runs at approximately the same speed per iteration as gapped BLAST, but in many cases is much more sensitive to weak but biologically relevant sequence similarities. PSI-BLAST is used to uncover several new and interesting members of the BRCT superfamily.

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Crossref · 10.1093/nar/25.17.3389

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  • Well-defined and widely accepted stochastic models for the evolution of protein sequences are available.

    “Fortunately, however, we do in fact have ready-to-use, well defined, and widely accepted stochastic models for the evolution of protein sequences.”

    From On universal common ancestry, sequence similarity, and phylogenetic structure: the sins of P-values and the virtues of Bayesian evidence (2011) · cites this paper as [31]

    The Statistical Preliminaries section (page not available) describes a probabilistic model for random protein sequences and calls PAM and BLOSUM substitution matrices popular. It does not establish that these are ready-to-use stochastic models of protein-sequence evolution; the random-sequence model is used to assess alignment scores, not to describe evolution. (LLM, conf=0.76)

    Experimental — accuracy not yet measured
  • After initial gene predictions, each set of gene models was screened for internal redundancy using BLASTP, with redundancy defined by 90% identity, bit score ≥100, and shorter length.

    “After initial gene predictions in each of the three sets of genomic scaffolds, we screened each set of gene models for internal redundancy with the BLASTP program from NCBI's BLAST 1 software suite 43 . A model was considered redundant if it: had 90% identity to other model; the alignment between the two models had a bit score of at least 100; and the model was shorter than the other model.”
  • The known mRNA sequences with full-length cds of sweet potato available in GenBank were used as a 'gold standard' reference to evaluate the quality of the assemblies by BLASTN.

    “The known mRNA sequences with full-length cds of sweet potato available in GenBank were considered as ‘gold standard’ reference in this study, and used to blast against each assembly by BLASTN [80].”
  • BLAST analysis indicated that amplification with the two oligonucleotides would only occur when a Plasmodium spp. was available to act as a template.

    “A BLAST analysis (1) of GenBank indicated that amplification with these two oligonucleotides would only occur when a Plasmodium spp. was available to act as a template (expected value of 0.31 for both oligonucleotides).”
  • The likelihood of a phylogenetic tree is not simply a function of the similarities of the sequences; it is also a function of the nested pattern of similarities in the data.

    “This means that the likelihood of a tree is not simply a function of the similarities of the sequences [31,101,102]. Rather, the likelihood of a phylogenetic tree is also a function of the nested pattern of similarities in the data.”

    From On universal common ancestry, sequence similarity, and phylogenetic structure: the sins of P-values and the virtues of Bayesian evidence (2011) · cites this paper as [31]

    The Sequence weights section discusses how related sequences affect alignment-based score matrices, not the likelihood of a phylogenetic tree. Searches for tree likelihood, topology, and nested patterns of similarity found no passage in our copy addressing the cited claim. (LLM, conf=0.76)

    Experimental — accuracy not yet measured

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Cites

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10 of the 94 references couldn’t be matched to a known paper.

Research works printed but not linked: 16

  1. [2]2. Pearson,W.R. and Lipman,D.J. (1988) Proc. Natl. Acad. Sci. USA, 85, 2444-2448.
  2. [4]4. Chao,K.-M., Pearson,W.R. and Miller,W. (1992) Comput. Appl. Biosci., 8, 481-487.
  3. [8]8. Karlin,S. and Altschul,S.F. (1990) Proc. Natl. Acad. Sci. USA, 87, 2264-2268.
  4. [18]18. Henikoff,S. and Henikoff,J.G. (1992) Proc. Natl. Acad. Sci. USA, 89, 10915-10919.
  5. [19]19. Wilbur,W.J. and Lipman,D.J. (1983) Proc. Natl. Acad. Sci. USA, 80, 726-730.
  6. [20]20. Robinson,A.B. and Robinson,L.R. (1991) Proc. Natl. Acad. Sci. USA, 88, 8880-8884.
  7. [21]21. Karlin,S. and Altschul,S.F. (1993) Proc. Natl. Acad. Sci. USA, 90, 5873-5877.
  8. [28]28. McLachlan,A.D. (1983) J. Mol. Biol., 169, 15-30. Downloaded from https://academic.oup.com/nar/article/25/17/3389/1061651 by guest on 24 June 2023 29
  9. [34]34. Gribskov,M., McLachlan,A.D. and Eisenberg,D. (1987) Proc. Natl. Acad. Sci. USA, 84, 4355-4358.
  10. [36]36. Stormo,G.D. and Hartzell,G.W. III (1989) Proc. Natl. Acad. Sci. USA, 86, 1183-1187.
  11. [37]37. Tatusov,R.L., Altschul,S.F. and Koonin,E.V. (1994) Proc. Natl. Acad. Sci. USA, 91, 12091-12095.
  12. [53]53. Brown,M., Hughey,R., Krogh,A., Mian,I.S., Sjölander,K. and Haussler,D. (1993) In Hunter,L., Searls,D. and Shavlik,J. (eds.), Proceedings of the First International Conference on Intelligent Systems for Molecular Biology. AAAI Press, Menlo Park, CA, pp. 47-55.
  13. [55]55. Karplus,K. (1995) In Rawlings,C., Clark,D., Altman,R., Hunter,L., Lengauer,T. and Wodak,S. (eds.), Proceedings of the Third International Conference on Intelligent Systems for Molecular Biology. AAAI Press, Menlo Park, CA, pp. 188-196.
  14. [83]83. Fitch,W.M. and Smith,T.F. (1983) Proc. Natl. Acad. Sci. USA, 80, 1382-1386.
  15. [86]86. Altschul,S.F. Proteins, in press. 87
  16. [90]90. Fulton,L. and Waterston,R. (1995) GenBank accession no. 1176713. Downloaded from https://academic.oup.com/nar/article/25/17/3389/1061651 by guest on 24 June 2023

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Authors
Altschul, S.
Affiliations
National Institutes of Health (US)
Corresponding author
Altschul, S.
Venue
Nucleic Acids Research
Published
1997-09-01
Volume
25
Issue
17
Pages
3389-3402
ISSN
  • 0305-1048 (ISSN-L)
  • 1362-4962
OpenAlex
W2158714788
Cited by
73,302
References
94
Citations by year
2026: 1121 · 2025: 1665 · 2024: 1892 · 2023: 1802 · 2022: 2307 · 2021: 2555 · 2020: 2507 · 2019: 2405 · 2018: 2390 · 2017: 2358 · 2016: 2551 · 2015: 2748 · 2014: 3024 · 2013: 3230 · 2012: 3272
FWCI
86.91
Type
journal article
Language
en
Open access
Locations
  • Nucleic Acids Research (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • National Institutes of Health (2r01lm005110-08)
  • U.S. National Library of Medicine (LM05110)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Genomics and Phylogenetic Studies
  • Physical Sciences › Computer Science › Artificial Intelligence › Algorithms and Data Compression
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Fractal and DNA sequence analysis
Keywords
PSI-BLAST, sequence similarity
MeSH terms
Algorithms, Amino Acid Sequence, Animals, DNA, Humans, Molecular Sequence Data, Proteins, Software, Databases, Factual, Sequence Alignment

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