2. Protein A participates in fertilization. Below is a diagram of the protein. It has 468 amino acids. Two mutations have been isolated. Mutation #1 is a single base pair deletion (G in yellow highlights) in the coding region, corresponding to around the 200th amino acid in the protein. Mutation #2 is a 6 base pair deletion (yellow highlights) towards the end of the protein (green highlighted TAA is the stop codon). aal mutation #1 DNA sequence (sense strand): 5'......AAAATGGTAAAGGCCGTCGTAGGATTCGGCGCT ... 3' corresponding wildtype sequence: 5' ..AAAATGGTAAAGGCCGTCGTAGGATTCGGCGCT ... 3' aa468 mutation #2 DNA sequence (sense strand): 5'......TACTGCCCATGCCCAGAGAGAAAGCGCAGACGCGTCTAA actgt... 3' corresponding wildtype sequence: 5'......TACTGCCCATGCCCAGAGAGAAAGCGCAGACGCGTCTAAactgt... 3' a). (10 points). In the above sequences, the open reading frame is indicated by alternating non-underlined and underlined triplets. Please use the codon table to deduce the amino acid sequence for the region shown in the wildtype protein. Wildtype AA sequence for the region around mutation #1: Wildtype AA sequence for the region around mutation #2: b). (10 points). Please make predictions what molecular change mutation #1 and mutation #2 cause. c). (5 points). Which mutation is more likely to abrogate the protein function? Why?

If the coding region of a gene (the exons) contains 2,100 base pairs of DNA, would a missense mutation cause a protein to be shorter, longer, or the same length as the normal 700 amino acid proteins? What would be the effect of a nonsense mutation? A sense mutation?

What is the start codon? What are the stop codons? Do any of them code for amino acids?

Given the following tRNA anticodon sequence, derive the mRNA and the DNA template strand. Also, write out the amino acid sequence of the protein encoded by this message. tRNA: UAC UCU CGA GGC mRNA: protein: How many hydrogen bonds would be present in the DNA segment?

The following is a portion of a protein: met-trp-tyr-arg-gly-pro-thr-Various mutant forms of this protein have been recovered. Using the normal and mutant sequences, determine the DNA and mRNA sequences that code for this portion of the protein, and explain each of the mutations. a. met-trp- b. met-cys-ile-val-val-leu-gln- c. met-trp-tyr-arg-ser-pro-thr- d. met-trp-tyr-arg-gly-ala-val-ile-ser-pro-thr-

Helicase Unwinding of the E. coli Chromosome Hexameric helicases, such as DnaB, the MCM proteins, and papilloma virus El helicase (illustrated in Figures 16.22 to 16.25), unwind DNA by passing one strand of the DNA duplex through the central pore, using a mechanism based on ATP-dependent binding interactions with the bases of that strand. The genome of E. coli K12 consists of 4,686,137 nucleotides. Assuming that DnaB functions like papilloma virus El helicase, from the information given in Chapter 16 on ATP-coupled DNA unwinding, calculate how many molecules of ATP would be needed to completely unwind the E. coli K 12 chromosome.

A scientist discovers a virus encoding a Protein X that degrades a subunit of the elF4F complex. Knowing that this virus transcribes its own mRNAs in the cytoplasm of human cells, why would Protein X be an effective virulence factor?

An unprocessed pre-mRNA has the following structure. Which of the following is not a possible size (in bp) of the mature mRNA? 205bp 180bp 150bp 100bp

Most codons specify an _________ . a. protein c. amino acid b. polypeptide d. mRNA

A normal mRNA that reads 5’ - UGCCAUGGUAAUAACACAUGAGGCCUGAAC- 3’ has an insertion mutation that changes the sequence to 5' -UGCCAUGGUUAAUAACACAUGAGGCCUGAAC- 3’. Translate the original mRNA and the mutated mRNA, and explain how insertion mutations can have dramatic effects on proteins. (Hint: Be sure to find the initiation site.)