BIOL239 Lecture : Eukaryotes Enzymes, parts of promoters, Basal factors, TBPs, Enhancers & Repressors, how they work, Gene Silencing.

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sapphireherring895

16 Oct 2011

School

University of Waterloo

Department

Biology

Course

BIOL239

Professor

Christine Dupont

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Document Summary

Core promoter: absolutely required for initiation of transcription. Taata box is -30 position and not same sequence (remember -10 position in prokaryotes) Basal factors: required for binding to the promoter to maintain a basal level of transcription. One basal factor is called tbp = tatat binding protein. Tbp comes in, binds to promoter, tafs (tatat binding protein association factors) bind. Activator proteins: bind to enhancer sequences to increase transcription. Two binding domains: dna binding domain, transcription-activation domain (see slide 13) The activator, which is bound to the promoter, also binds to the tbp (dna curves around) and transcription increases. **most eukaryotic activators have to for dimers to function. Transcription factor must bind to testosterone before it can bind to enhancer because testosterone causes the transcription factor to change into its necessary shape. This allows enhancer to bind to basal factors. **enhanced leved of transcrpition** repressors - diminish transcriptional activity. Could bind to enhancer which blocks activator (competitive)

Related Questions

Eukaryotic transcription normally takes place on a chromatin template at nuclease-accessible sites.(True/False)

*After promoter clearance by RNA polymerase II:

A) all associated factors remain bound to the polymerase for elongation.

B) a subset of factors remain at the promoter region.

*Which of the following statements is FALSE?

A) RNA polymerase II is responsible for the transcription of genes encoding protein-coding sequences only.

B) Many promoters recognized by RNA polymerase II contain regulatory elements several kbp upstream of the initiation site.

C) TFIIB has a role in converting a closed-promoter into an open-promoter complex.

D) The C-terminal domain of the largest subunit of RNA pol II undergoes extensive phosphorylation prior to transcription elongation.

E) A multiprotein complex is involved in communication between upstream control elements and proteins bound at the promoter.

C) no further elongation factors are acquired by the polymerase.

D) no further chromatin remodeling is required.

E) transcription continues until the polymerase reaches the poly (A) tail

*In eukaryotes RNA polymerase I transcribes all of the ribosomal RNA components.(TRUE/FALSE)

What are proteins that initiate transcription in eukaryotes by recognizing sequences within the promoter region of a gene and attracting RNA polymerase?

a)transcription factors

b)TATA boxes

c)poly A tails

d)inducers

e)repressors

viridianbadger569

1 DNA sequences found in introns provide [A] amino acid sequence information.

[B] regulatory information.
[C] no known useful information.

[D] structure for the gene.
[E] alternative DNA splicing possibilities.

3. The TATA box is a(n)
[A] sequence close to the promoter region of many genes.
[B] square-shaped sequence.
[C] enhancer consensus sequence.
[D] activator sequence necessary for proper translation.
[E] None of the above

5. Regarding genes and gene expression, which of the following is not a difference between prokaryotes and eukaryotes
[A] Eukaryotic DNA does not contain a TATA box close to the initiation site as does prokaryotic DNA.

[B] In eukaryotes, RNA polymerase requires

'transcription factors'or initiation.

[C] Prokaryotic genes are often grouped together in

operons.

[D] In eukaryotes, the regulation of several genes at once requires common control elements in each of the genes.
[E] There is a diversity of eukaryotic polymerases that is reflected in the diversity of eukaryotic promoters.

10) In eukaryotic cells, a repressor

[A] is made of DNA.
[B] binds to the enhancer region to block transcription. [

C] is located both upstream and downstream from the promoter.
[D] binds to the operator to block RNA polymerase.

[E] binds to a silencer to reduce transcription rates.

Coordinated regulation of genes in eukaryotic cells [A] is the result of positioning the same regulatory sequence in front of each gene.
[B] results from all of those genes being under the control of one promoter.

[C] occurs because related genes all have the same

operons.
[D] occurs because enhancers cause DNA to bend.

BIOL239 Lecture : Eukaryotes Enzymes, parts of promoters, Basal factors, TBPs, Enhancers & Repressors, how they work, Gene Silencing.

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