BIOB11H3 Chapter 11: Chapter 11 notes

Your assigned Protein: DNA polymerase III holoenzyme

a.) What is the function of your protein?

b.) Where does the protein perform its function?

c.) Is it embedded in a membrane, part of an organelle, an enzyme, exported from the cell?

d.) What is the structure of DNA polymerase III holoenzyme?

e.) How many polypeptides does DNA polymerase III holoenzymehave?

f.) How many amino acids long is each polypeptides in DNA polymerase III holoenzyme?

g.) If there is more than one polypeptide: are all the polypeptides different? Are any identical? How would you describe the overall arrangement?

h.) Sketch a model and approximate the overall shape and the presence of secondary and tertiary structure?

While one gene usually specifies one enzyme, which of thefollowing is not true?

1) Explain how the Ames test can be used to detect potential mutagens? What are the limitations of this test?

2) The base pair sequence of a region of a gene coding for a polypeptide is:

Strand A: 5’ C A C C T A A C T T A C T C A G* C T T A C G A A G T C T A C C C A G C G 3’

Strand B: 3’ G T G G A T T G A A T G A G T C* G A A T G C T T C A G A T G G G T C G C 5’

A.) If this gene codes for a polypeptide that contains three Tyrosines (Tyr), which strand is transcribed? (1 pt)

B). What is the nucleotide of the mRNA transcribed from this DNA? (Note: there is no “start” codon. Simply start from the “appropriate” end). You MUST label the appropriate 5 ‘ and 3’ ends.

C.) What is the polypeptide sequence of the protein translated from this mRNA?

D.) Hydroxylamine (HA) affects the bold-faced (*) base pair and causes a mutation during DNA replication. What is the amino acid sequence of the polypeptide coded by the mutant gene?