CISC 4020 Bioinformatics Monday, February 14

Lab Exercise #2: Pairwise Sequence Alignment

(due February 22 – submit on Blackboard)

Resources: NCBI BLAST: www.ncbi.nlm.nih.gov/BLAST/ Entrez: www.ncbi.nlm.nih.gov/Entrez/

1) Michael Crichton's fantasy about cloning dinosaurs, Jurassic Park contains a putative dinosaur DNA sequence. Use nucleotide-nucleotide BLAST against the “Nucleotide collection” database to identify the real source of the following sequence:

>DinoDNA "Dinosaur DNA" from Crichton's JURASSIC PARK p. 103 nt 1-1200 GCGTTGCTGGCGTTTTTCCATAGGCTCCGCCCCCCTGACGAGCATCACAAAAATCGACGC GGTGGCGAAACCCGACAGGACTATAAAGATACCAGGCGTTTCCCCCTGGAAGCTCCCTCG TGTTCCGACCCTGCCGCTTACCGGATACCTGTCCGCCTTTCTCCCTTCGGGAAGCGTGGC TGCTCACGCTGTACCTATCTCAGTTCGGTGTAGGTCGTTCGCTCCAAGCTGGGCTGTGTG CCGTTCAGCCCGACCGCTGCGCCTTATCCGGTAACTATCGTCTTGAGTCCAACCCGGTAA AGTAGGACAGGTGCCGGCAGCGCTCTGGGTCATTTTCGGCGAGGACCGCTTTCGCTGGAG ATCGGCCTGTCGCTTGCGGTATTCGGAATCTTGCACGCCCTCGCTCAAGCCTTCGTCACT CCAAACGTTTCGGCGAGAAGCAGGCCATTATCGCCGGCATGGCGGCCGACGCGCTGGGCT GGCGTTCGCGACGCGAGGCTGGATGGCCTTCCCCATTATGATTCTTCTCGCTTCCGGCGG CCCGCGTTGCAGGCCATGCTGTCCAGGCAGGTAGATGACGACCATCAGGGACAGCTTCAA CGGCTCTTACCAGCCTAACTTCGATCACTGGACCGCTGATCGTCACGGCGATTTATGCCG CACATGGACGCGTTGCTGGCGTTTTTCCATAGGCTCCGCCCCCCTGACGAGCATCACAAA CAAGTCAGAGGTGGCGAAACCCGACAGGACTATAAAGATACCAGGCGTTTCCCCCTGGAA GCGCTCTCCTGTTCCGACCCTGCCGCTTACCGGATACCTGTCCGCCTTTCTCCCTTCGGG CTTTCTCAATGCTCACGCTGTAGGTATCTCAGTTCGGTGTAGGTCGTTCGCTCCAAGCTG ACGAACCCCCCGTTCAGCCCGACCGCTGCGCCTTATCCGGTAACTATCGTCTTGAGTCCA ACACGACTTAACGGGTTGGCATGGATTGTAGGCGCCGCCCTATACCTTGTCTGCCTCCCC GCGGTGCATGGAGCCGGGCCACCTCGACCTGAATGGAAGCCGGCGGCACCTCGCTAACGG CCAAGAATTGGAGCCAATCAATTCTTGCGGAGAACTGTGAATGCGCAAACCAACCCTTGG CCATCGCGTCCGCCATCTCCAGCAGCCGCACGCGGCGCATCTCGGGCAGCGTTGGGTCCT

2) Mark Boguski of the NBCI noticed this and supplied Crichton with a better sequence for the sequel, The Lost World. Identify the most likely source of this sequence using nucleotide- nucleotide BLAST.

>DinoDNA "Dinosaur DNA" from Crichton's THE LOST WORLD p. 135 GAATTCCGGAAGCGAGCAAGAGATAAGTCCTGGCATCAGATACAGTTGGAGATAAGGACG GACGTGTGGCAGCTCCCGCAGAGGATTCACTGGAAGTGCATTACCTATCCCATGGGAGCC ATGGAGTTCGTGGCGCTGGGGGGGCCGGATGCGGGCTCCCCCACTCCGTTCCCTGATGAA GCCGGAGCCTTCCTGGGGCTGGGGGGGGGCGAGAGGACGGAGGCGGGGGGGCTGCTGGCC TCCTACCCCCCCTCAGGCCGCGTGTCCCTGGTGCCGTGGGCAGACACGGGTACTTTGGGG ACCCCCCAGTGGGTGCCGCCCGCCACCCAAATGGAGCCCCCCCACTACCTGGAGCTGCTG CAACCCCCCCGGGGCAGCCCCCCCCATCCCTCCTCCGGGCCCCTACTGCCACTCAGCAGC GGGCCCCCACCCTGCGAGGCCCGTGAGTGCGTCATGGCCAGGAAGAACTGCGGAGCGACG GCAACGCCGCTGTGGCGCCGGGACGGCACCGGGCATTACCTGTGCAACTGGGCCTCAGCC TGCGGGCTCTACCACCGCCTCAACGGCCAGAACCGCCCGCTCATCCGCCCCAAAAAGCGC CTGCTGGTGAGTAAGCGCGCAGGCACAGTGTGCAGCCACGAGCGTGAAAACTGCCAGACA TCCACCACCACTCTGTGGCGTCGCAGCCCCATGGGGGACCCCGTCTGCAACAACATTCAC GCCTGCGGCCTCTACTACAAACTGCACCAAGTGAACCGCCCCCTCACGATGCGCAAAGAC GGAATCCAAACCCGAAACCGCAAAGTTTCCTCCAAGGGTAAAAAGCGGCGCCCCCCGGGG GGGGGAAACCCCTCCGCCACCGCGGGAGGGGGCGCTCCTATGGGGGGAGGGGGGGACCCC TCTATGCCCCCCCCGCCGCCCCCCCCGGCCGCCGCCCCCCCTCAAAGCGACGCTCTGTAC GCTCTCGGCCCCGTGGTCCTTTCGGGCCATTTTCTGCCCTTTGGAAACTCCGGAGGGTTT TTTGGGGGGGGGGCGGGGGGTTACACGGCCCCCCCGGGGCTGAGCCCGCAGATTTAAATA ATAACTCTGACGTGGGCAAGTGGGCCTTGCTGAGAAGACAGTGTAACATAATAATTTGCA CCTCGGCAATTGCAGAGGGTCGATCTCCACTTTGGACACAACAGGGCTACTCGGTAGGAC CAGATAAGCACTTTGCTCCCTGGACTGAAAAAGAAAGGATTTATCTGTTTGCTTCTTGCT GACAAATCCCTGTGAAAGGTAAAAGTCGGACACAGCAATCGATTATTTCTCGCCTGTGTG AAATTACTGTGAATATTGTAAATATATATATATATATATATATATCTGTATAGAACAGCC TCGGAGGCGGCATGGACCCAGCGTAGATCATGCTGGATTTGTACTGCCGGAATTC

3) Viral reverse transcriptase, such as the pol gene product encoded by HIV-1, have human homologs. The GenBank accession number for HIV-1 reverse transcriptase is NP_057849. (Use Entrez to confirm the accession number.) A search of Entrez reveals many human viral-related gene products, including a retrovirus-related Pol polyprotein of 874 amino acid residues (P10266). Perform a pairwise alignment using the blastp program.

The default conditions for this search include the use of the BLOSUM62 scoring matrix. The expect value is about 1 x 10-67 , indicating that the proteins are closely related even though they share only 28% identity over a span of 761 amino acids. Repeat the analysis using the BLOSUM62, BLOSUM45, and BLOSUM80 scoring matrices. What is the effect of changing the search parameters?

4) Next perform pairwise alignments of the proteins described in exercise 3 using the PAM30 and PAM70 matrices. What are the expect values? What span of amino acid residues is aligned? Are the search results using different PAM matrices similar or different to the results of using different BLOSUM matrices?

5) Compare modern human mitochondrial DNA to extinct Neanderthal DNA. First obtain the nucleotide sequence of a mitochondrially encoded gene, cytochrome oxidase in Neanderthals. Next, perform a BLAST search on the human genome, note the most significant alignment and record the percent nucleotide identities.

6) Is a hippopotamus more closely related to a pig or to a whale? To answer this question, first find the protein sequence of hemoglobin from each of these three organisms. Next, perform pairwise sequence alignments and record amino acid identities.