chapter 8 part 2 Flashcards
Where is the principal binding site for transcription factors in most eukaryotic promoters?
the TATA box
where does transcription in eukaryotes take place?
the nucleus
Which structure, located in the promoter, facilitates the binding of RNA polymerase III to tRNA promoters?
internal control region (ICR)
what enzyme permits a 5’ capping of mRNA?
guanylyl transferase
Which DNA regulatory sequence interacts with activator proteins to increase the level of transcription?
enhancer
Which of the following research techniques would be used to verify that a DNA sequence of interest binds to a transcription factor?
band shift assay
what is the most common eukaryotic consensus sequence?
the TATA Box
what is the TATA box also called?
the Goldberg-Hogness box
where is the TATA Box located?
about the -25 position
whare is the CAAT box found?
-80 position
where is the GC-rich box found?
the -90 position
do prokaryotic promoters display more or less variation than eukaryotic promoters?
less
what helps RNA pol II bind to the promoter sequence?
transcription factos (TFs)
what is the principle binding site during promoter recognition?
the TATA Box
what do TFs bind to and what do they do?
nearby regulatory sequences and they interact with RNA polymerase
what are the TFs called that interact with Pol II?
TFII Factors
what does TFIID contain?
the TATA-Binding protein
what does the TFIID bind?
it binds the TATA Box sequence and the TBP-associated factor (TAF)
what froms the initial committed complex?
the TFIID bound to the TATA Box
what makes up the minimal initation complex?
the TFIIB, TFTTF, and RNA Pol ii
what form the complete initation complex?
TAFIIE and TFIIH
what are the proteins in the complete initiation complex referred to as?
the General Transcription Factors (GTFs)
what happens in Band Shift Assay?
-isolate fragements of DNA containing suspected DNA fragments
-DNA fragments r mixed with RNA pol and/or transcription factors
-the fragments that bind to the RNA/ TFS have slower electrophoretic migration that the unbound sequences
-inidcated that the DNA fragments r bound by transcriptional proteins
is exact location known in Band Shift Assay?
No- we just know that the DNA is bound by transcriptional proteins
what happens in DNA Footprint Protection Assay?
-first couple of steps are identical to band assay
-the fragments are labeled with 32P
-Dnase I is added to each reaction (DNA not protected by proteins is cleaved)
-All fragments from both reactions are subjected to electrophoresis
is exact location known in DNA Footprint Protection Assay?
Yes- we get to know where within a fragment a transcriptional protein binds
what does Dnase I do?
it randomly gets rid of DNA not protected by proteins
Mutations inside the consensus region significantly _________ levels of transcription
reduce
Mutations outside the consensus region have ________________ effects on transcription
non-significant