PDF-Basic Local Alignment Sequence Tool BLAST

Outline I ntroduction BLAST s earch s teps Step 1 Specifying Sequence of interest Step 2 Selecting BLAST Program Step 3 Selecting a Database Step 4 Selecting Search Parameters and Format. Basic Local Alignment Search Tool. (Altschul et al. 1990. ). What is blast. ?. BLAST .  DNA/protein databases. GOOGLE  internet. . D. Fristrom, Boston U. .. Uses for Blast. . Identifying unknown sequence. output. How to . measure. the similarity between two sequences. Q: which one is a better match to the query ?. Query: . M. . A T. . W . L. . . Seq_A: . M. . A T. P P . Seq_B: . M. P P . W . Jeremy Buhler (. in absentia. ). Wilson Leung 07/2015. Key limitations of the . Smith. -Waterman . local. alignment algorithm. Quadratic. . in time and space complexity. Report only . one optimal alignment. Mohammed Mehdi Rizvi. Molecular Lab Techniques 446. Background. BLAST is the . B. asic . L. ocal . A. lignment . S. earch . T. ool. . It is an algorithm used for comparing sequences, such as amino acid sequences of proteins, or the nucleotides of DNA sequences.. Recap : . Pairwise. sequence alignment. Grouping of two sequences to maximize similarity/identity using a scoring system (substitution matrices):. PAM (1,120,250). BLOSUM (80,62,45). Optimal alignment algorithms:. Thermo Fisher / Open Biosystems. Dr. Krishnan K. . Chittur. University of Alabama in Huntsville. Dr. Joseph Ng. University of Alabama in Huntsville. What is BLAST. B.L.A.S.T. stands for . B. asic . L. 1. Data structure: Lookup Table. Application: BLAST . 2. The Look-up Table Data Structure. A . k-mer . is a string of length . k.. A . lookup table. is a table of size . |. Σ. |. k. . that stores the location of all . Concepts. Introduction to Biostatistics and Bioinformatics. Sequence . Database Searching. This Lecture. Stuart M. Brown, Ph.D.. Center for Health Informatics and Bioinformatics. NYU School of Medicine. ). Design. Curation. Data Mining. Computational Biology. . Tools for:. Sequence analysis. Structure prediction. Docking. Structural genomics. Functional genomics. Proteomics . Interactomics. BIOINFORMATICS. Hardison. Genomics 4_1. Sources: Webb Miller (Penn State. ). Kun-Mao Chao and . Luxin. Zhang: . Sequence Comparisons, Theory . and Methods. , Springer 2008. Bill Pearson (U. Virginia). Vladimir . Lukic.   Understanding the BLAST (Basic Local Alignment Search Tool) Program and a Step-by-step Guide for its use in Life Science Research Kailash Chandra Samal, Jyoti Prakash S Post-Doctoral Fellow. Ochman. Lab. Global . vs. Local Alignments. Global . . The global approach is useful when you are comparing a small group of sequences, but becomes become computationally expensive as the number of sequence in the comparison increases. . online and offline. Wen-Dar Lin. Bioinformatics core, IPMB. wdlin@gate.sinica.edu.tw. Preface. When we are talking about . sequence similarity. , we usually are talking about . local alignments. .. NCBI BLAST is one of the most famous local alignment programs where almost everyone has ever used it.. Altschul. . et.al. , 1990. . 傅安. . 陳岳昇. . . 陳宗涵. 2016.12.12. Outline. Introduction and Methods. Results. Conclusion. Introduction. Measures of similarity between sequences to distinguish biologically significant relationships..