Assignment #1, v. 1.1B

Please paste this assignment into a word processor program and place your answers below each of the questions.

Using the GenBank accession number M28668 as a starting point, answer the following questions:

1.What GenBank sequence does the accession number specify?  What does this sequence encode?

2.How many bases of sequence are in the file?  How many total in GenBank (as of this date)?

3.Use Medline to answer the following questions:

a. Is this transcript present in patients with the "disease?'

b. What two domains are present in the protein?

c. Which amino acid is missing in patients with the "disease?"

d. From what tissue was this sequence derived?

4.How many bases are in the processed transcript?

5.How many "g" residues appear in the reported sequence?  Calculate the G+C ratio of this sequence.

6.At what specific bases does the start codon appear?  At what specific base does the stop codon appear?  Which of the three stop codons is used? 

7.Attempt to retreive the entire genomic DNA sequence for this gene.  Why do you think this is a problem?

8.How many introns are removed as the primary transcript is processed?

9.What is the accession number for the protein sequence corresponding to the nucleic acid sequence specified above?  Retrieve this file to answer the next series of questions.

11.How many amino acids are there in this protein?  What are the first five amino acids beginning at position 141 (please use full names - no abbreviations)?

12.How large is the gene that when mutated causes the disease? (HINT: Search OMIM through Entrez with 'cystic fibrosis' as a query. Do you need to use Boolean operators or parentheses?).  Are there any other disorders that are caused by mutattions in this gene?

13.Where does this gene map in the human genome?   What two markers is this gene between?  What is encoded by these flanking markers?