Exam 13: Regulation of Gene Expression in Bacteria and Bacteriophage

For the following gene, which mutant likely has lost its enhancer? Mutant \# Deletion Region \% Transcription WT None 100\% 1 1-200 130\% 2 250-400 100\% 3 500-800 50\% 4 950-1100 0\%

Gal80 is mutated such that it cannot interact with Gal3. What effect would you expect to see in the presence of galactose?

A transcription factor that binds to a gene first and facilitates the binding of other transcription factors is called a__________ .

If you want to affect chromatin packaging, which amino acid could you mutate to affect both histone acetylation and methylation patterns?

Which protein complex directs DNA bending into loops that contact RNA polymerase and transcription factors bound at the core promoter or with protein complexes bound to proximal promoter elements?

Chromatin remodeling involves both sliding and relocating of the nucleosomes. Which eukaryotic chromatin remodeling complex is likely involved?

Demethylation and acetylation lead to open chromatin structure and are associated with _______regions of genomes.

For the following gene, MspI and HpaII restriction sites and their positions are indicated here. Recall that HpaII is methylation sensitive, while MspI is not. If this gene is being actively transcribed, how many fragments would you expect from this restrictio digest?

For the following gene, you notice the following results. Mutant \# Deletion Region \% Transription (lungs) \% Transaription (kid) WT None 100\% 100\% 1 1-200 130\% 130\% 2 250-400 100\% 100\% 3 500-800 50\% 50\% 4 950-1100 0\% 100\% What type of sequence has been mutated in mutant 4?

In the GAL gene system,________ are cis- acting regulatory elements, and__________ protein is a trans- acting regulatory protein.

Many types of cancer are known to overexpress the receptor protein tyrosine kinase. Which molecular technique can be used to reduce expression of tyrosine kinase in cell culture?

Scientists can create transgenic organisms by inserting foreign DNA randomly into the chromosomes of a host. A scientist might do this in order to express genes carried in the foreign DNA and in this case the foreign DNA is often engineered to include insulator sequences at the ends of the foreign sequence. Explain why insulators would be useful in this context.

RNA polymerase can bind to _______ to generate different mRNAs from the same gene.

A region of chromatin has recently become DNAse I hypersensitive. Which enzyme has been activated to cause this change in chromatin structure?

In the GAL gene system, which protein acts as an activator protein through its transcription- initiating effect?

How does transcription inhibition differ between prokaryotes and eukaryotes? Describe the two mechanisms used by eukaryotes to direct the enhancers toward certain promoters and away from others.

Which of the following would you expect to show the least evolutionary conservation?

Which molecules bind regulatory sequences of DNA to encourage positive regulation of transcription?

Inherited traits that can change without affecting the sequence of DNA are examples of what?

What are the protein- binding sequences that direct enhancers to interact with the intended promoter and that block communication between enhancers and other promoters?