Purchase Solution

Molecular Biology - DNA & Mutant E.coli Genotypes

Not what you're looking for?

Ask Custom Question

Please see the attached file for full problem description.

1. Heparin is a polyanion that inhibits RNA transcription in vitro by binding directly to bacterial RNA polymerase (RNAP). If heparin interferes with the ability of the polymerase to bind DNA in a non-specific fashion, what subunit of RNAP is the heparin binding to?

2. The 5' end of the codon strand of a prokaryote gene is diagramed below.
a. Which region(s) would most likely be protected from digestion by Dnase in the presence of the RNAP holoenzyme?
b. What would be the sequence of the 5' end of the encoded mRNA?
c. Upon transcription of this DNA, which region would contain the first codon to be translated?

3. A mutant of E.coli has constitutive expression of beta-galactosidase. A partial diploid formed with this mutant and F' I^+ O^+ Z^+ has normal, inducible synthesis of beta-galactosidase. What is the genotype of the mutant?

4. A mutant of E.coli cannot synthesis beta-galactosidase or beta-galactosidase permease in the presence or absence of lactose. A partial diploid formed with this mutant and F' I^+ O^c Z^+ Y^+ also cannot be induced to synthesize either enzyme. What possible genotypes could the mutant have?

Purchase this Solution

Solution Summary

The solution answers the questions with explanation in approximately 350 words.

Solution Preview

1. The bacterial RNAP is composed of 5 subunits: two alphas, one beta, one beta-prime, and sigma. Sigma is involved in RNAP's DNA binding to the promoter region. If heparin prevents RNAP binding to DNA, then it must interacts with the sigma subunit of RNAP.

2. a) The RNAP binds tightly to its promoter. Two regions have to be present in the promoter: The "TATAAT box" near the -10 region, and the TTGACA sequence near the -35 region. RNAP will bind these ...

Purchase this Solution

Free BrainMass Quizzes
Birth 101

Do you know about childbirth? Find out with this quiz.

Parts of the Brain

This quiz will test your knowledge on different areas of the brain.

Infant Development: Sleep

How much do you know about infant sleep? Test your knowledge with this quiz.

The Heart

This quiz test the understanding of the heart and some of its parts. It is important to understand how the heart functions and what makes it function.

The Plant Body

This quiz will test your knowledge of the anatomy of a common plant.