BCHM 4360 Exam II Questions and ANSWERs 100%
Pass
In the late stages of flagellum protein synthesis, the anti-sigma factor is exported
from the cell so the sigma factor can promote assembly gene transcription,
allowing the flagellum to be put together.
Eukaryotic and archaeal promoters also need extra proteins to target the core
enzyme to promoters: _______ _____________ _______. - ANSWER -general
transcription factors
The TFII complex works with RNA Polymerase ___ to form the ___-_________
complex. - ANSWER -II, pre-initiation
What is the function of TFIIA? - ANSWER -stabilizes binding of TBP and TFIIB
What is the function of TFIIB? - ANSWER -promoter recognition, stabilizes early
transcription complex
What is the function of TFIID? - ANSWER -promoter recognition, DNA bending
interacts with regulatory factors
What is the function of TFIIE? - ANSWER -recruits TFIIH
What is the function of TFIIF? - ANSWER -suppresses non-specific DNA
binding and captures non-template strand upon melting
What is the function of TFIIH? - ANSWER -unwinds promoter DNA,
phosphorylates CTD
True or False: All eukaryotic polymerases need the TATA binding protein (TBP)
to initiate transcription. - ANSWER -True
, What are three other elements besides the TBP or TATA box that are often present
in eukaryotic transcription? - ANSWER -TFIIB recognition element (BRE),
initiator element (INR), and downstream promoter element (DPE)
True or False: A TATA box is required for every single transcription event. -
ANSWER -False, although it is found about 95% of the time
What is the first step in assembling the transcription initiation complex? -
ANSWER -Binding of TFIID to the TATA box
How does TFIID bind to the TATA box? - ANSWER -Via TBP, which binds to
the minor groove of DNA, which induces strong distortions in the DNA and causes
local DNA unwinding
Some other components of TFIID, called TBP-_________ factors (TAFs) mediate
recognition of other promoter elements like ___ and ___. - ANSWER -associated,
INR, DPE
What is the next step in transcription initiation after TFIID has associated with
DNA? - ANSWER -TFIIB is recruited. This recognizes the BRE promoter element
and binds asymmetrically, helping to determine the transcription direction.
What is the next step in transcription initiation after TFIIB has bound? -
ANSWER -TFIIA binds and stabilizes the TBP-DNA interactions.
What is the next step in transcription initiation after TFIIA binds? - ANSWER
TFIIE and TFIIH bind, which catalyze ATP-powered unwinding of DNA
What are the two main components of the pre-inititation complex? - ANSWER
RNA Polymerase II and general transcription factors
True or False: The pre-initiation complex is good enough to initiate transcription
in vitro and in vivo. - ANSWER -False, in vivo requires additional protein
complexes
, Another large complex, ________, is needed to activate many Polymerase II
transcribed genes. - ANSWER -mediator
What are the main similarities between Pol I, II, and III? - ANSWER -Core
subunits are similar, all three use TBP to initiate transcription
What are the main differences between Pol I, II, and III? - ANSWER -TBP is part
of different complexes in each enzyme, each use different proteins to initiate
transcription, recognize different promoters, and have different general
transcription factors
Once RNA Polymerase is in position, the complex of polymerase and promoter is
called a ______ complex. - ANSWER -closed
Approximatel how many bp of duplex DNA (transcription bubble) does RNA
Polymerase open up? - ANSWER -14bp
True or False: ATP is required to open up the transcription bubble in all three
RNA Polymerases - ANSWER -False, only Pol II requires ATP
The RNA Polymerase bound to an open region of DNA is called the ____
complex. - ANSWER -open
RNA polymerase frequently fails to make a full length RNA on the first attempt,
which leads to the release of short RNAs of 2-9 nucleotides, and is called
________ initiation. - ANSWER -abortive
______________ is the key to release the tether attached to RNA Polymerase so
that RNA Polymerase can get going like it wants to. - ANSWER -phosphorylation
The non-template strand of DNA is held apart by which three regions of RNA
Polymerase? - ANSWER -lid, zipper, and rudder regions
Successive nucleotides are added at the __ end of the growing RNA molecule by
____________ attack, forming a _____________ bond and releasing
____________. - ANSWER -3', nucleophilic, phosphodiester, pyrophosphate
Pass
In the late stages of flagellum protein synthesis, the anti-sigma factor is exported
from the cell so the sigma factor can promote assembly gene transcription,
allowing the flagellum to be put together.
Eukaryotic and archaeal promoters also need extra proteins to target the core
enzyme to promoters: _______ _____________ _______. - ANSWER -general
transcription factors
The TFII complex works with RNA Polymerase ___ to form the ___-_________
complex. - ANSWER -II, pre-initiation
What is the function of TFIIA? - ANSWER -stabilizes binding of TBP and TFIIB
What is the function of TFIIB? - ANSWER -promoter recognition, stabilizes early
transcription complex
What is the function of TFIID? - ANSWER -promoter recognition, DNA bending
interacts with regulatory factors
What is the function of TFIIE? - ANSWER -recruits TFIIH
What is the function of TFIIF? - ANSWER -suppresses non-specific DNA
binding and captures non-template strand upon melting
What is the function of TFIIH? - ANSWER -unwinds promoter DNA,
phosphorylates CTD
True or False: All eukaryotic polymerases need the TATA binding protein (TBP)
to initiate transcription. - ANSWER -True
, What are three other elements besides the TBP or TATA box that are often present
in eukaryotic transcription? - ANSWER -TFIIB recognition element (BRE),
initiator element (INR), and downstream promoter element (DPE)
True or False: A TATA box is required for every single transcription event. -
ANSWER -False, although it is found about 95% of the time
What is the first step in assembling the transcription initiation complex? -
ANSWER -Binding of TFIID to the TATA box
How does TFIID bind to the TATA box? - ANSWER -Via TBP, which binds to
the minor groove of DNA, which induces strong distortions in the DNA and causes
local DNA unwinding
Some other components of TFIID, called TBP-_________ factors (TAFs) mediate
recognition of other promoter elements like ___ and ___. - ANSWER -associated,
INR, DPE
What is the next step in transcription initiation after TFIID has associated with
DNA? - ANSWER -TFIIB is recruited. This recognizes the BRE promoter element
and binds asymmetrically, helping to determine the transcription direction.
What is the next step in transcription initiation after TFIIB has bound? -
ANSWER -TFIIA binds and stabilizes the TBP-DNA interactions.
What is the next step in transcription initiation after TFIIA binds? - ANSWER
TFIIE and TFIIH bind, which catalyze ATP-powered unwinding of DNA
What are the two main components of the pre-inititation complex? - ANSWER
RNA Polymerase II and general transcription factors
True or False: The pre-initiation complex is good enough to initiate transcription
in vitro and in vivo. - ANSWER -False, in vivo requires additional protein
complexes
, Another large complex, ________, is needed to activate many Polymerase II
transcribed genes. - ANSWER -mediator
What are the main similarities between Pol I, II, and III? - ANSWER -Core
subunits are similar, all three use TBP to initiate transcription
What are the main differences between Pol I, II, and III? - ANSWER -TBP is part
of different complexes in each enzyme, each use different proteins to initiate
transcription, recognize different promoters, and have different general
transcription factors
Once RNA Polymerase is in position, the complex of polymerase and promoter is
called a ______ complex. - ANSWER -closed
Approximatel how many bp of duplex DNA (transcription bubble) does RNA
Polymerase open up? - ANSWER -14bp
True or False: ATP is required to open up the transcription bubble in all three
RNA Polymerases - ANSWER -False, only Pol II requires ATP
The RNA Polymerase bound to an open region of DNA is called the ____
complex. - ANSWER -open
RNA polymerase frequently fails to make a full length RNA on the first attempt,
which leads to the release of short RNAs of 2-9 nucleotides, and is called
________ initiation. - ANSWER -abortive
______________ is the key to release the tether attached to RNA Polymerase so
that RNA Polymerase can get going like it wants to. - ANSWER -phosphorylation
The non-template strand of DNA is held apart by which three regions of RNA
Polymerase? - ANSWER -lid, zipper, and rudder regions
Successive nucleotides are added at the __ end of the growing RNA molecule by
____________ attack, forming a _____________ bond and releasing
____________. - ANSWER -3', nucleophilic, phosphodiester, pyrophosphate
