Promoter Site...DAT Destroyer Error?

[bchang57]

---

Members don't see this ad.

This is for the 2012 version of DAT Destroyer, #373 of the Biology section:

The question asked basically what a promoter site is for. I figure it was a place where transcription starts or lets it know where to start, where regulatory proteins can bind, and a place where DNA and RNA polymerase bind (to start transcription)

Destroyer said it is ONLY a place where DNA and RNA polymerase bind to start transcription

Destroyer's explanation: The six-protein enzyme complex called RNA polymerase binds to a specific site on the DNA called the promoter site, hence determining where transciption begins. Transcription and translation have several differences prokaryotes and eukaryotes, but both employ a promoter site to determine where transcription begins.

Doesn't their explanation support that it's also where transcription begins? And also...can't regulatory proteins bind to the promoter region?

(Note: I can't put the entire question and answer out on the forum word for word due to copyright laws)

 

[Adamsswag]

You should look up the terms operator vs promoter. The promoter is located upstream from the operator. The operator can be controlled by regulatory proteins, that either repress or induce the process of transcription. The promoter is where the RNA polymerase binds to initiate transcription... Think about it like this: if the RNA polymerase binds to the promoter and initiates transcription, then this gives the "green light" for transcription to start at the operator (when we get downstream to the spot of the operator, that is)

 

[xtra333]

I was thinking C was correct also. I believe some transcription factors namely TFIID has to bind to the promoter and recruit the RNA polymerase via protein protein interactions. Therefore, the RNA polymerase cannot bind to the promoter without the presence of TFIID.

 

[bchang57]

yea in my molecular biology lab class lectures I remember my professor saying there are proteins that regulate at the promoter region....

but maybe the DAT just wants us to know things based strictly on their definition? err if that even makes sense...

 

[thejamespark]

This is for the 2012 version of DAT Destroyer, #373 of the Biology section:

What is a promoter site?

a) a start site for DNA replication
b) a start site for DNA transcription
c) the binding site for regulator proteins that will allow for transcription
d) the site on DNA at which RNA polymerase binds to initiate transcription
e) more than one of these

I chose answer choice e)

Destroyer's answer: d)
Explanation: The six-protein enzyme complex called RNA polymerase binds to a specific site on the DNA called the promoter site, hence determining where transciption begins. Transcription and translation have several differences prokaryotes and eukaryotes, but both employ a promoter site to determine where transcription begins.

Doesn't their explanation support answer choices b) and d)?? And also...can't regulatory proteins bind to the promoter region, thus making answer choice c) valid also?

definitely not C because thats what a operator is not promoter.
D is a yes because thats where RNA poly binds but B i prob would have agreed but i'm not sure why the answer is saying it isnt...

 

[ktran17]

It cannot be B because the promotor region is not where transcription occurs. Instead, transcription actually occurs downstream of the promotor region.
Here's a brief breakdown of transcription:
1. Transcription factors + RNA polymerase bind to the promotor region
2. RNA poly + transcription factors = basal transcriptional complex (BTC)
3. Stimulate the BTC with enhancers and other factors to increase basal transcriptional activity.
4. Transcription will now occur a little downstream of the promotor region.

It cannot be the regulatory protein choice as well, because TFIID and the like are transcription factors and not necessarily regulatory proteins. Although, to a certain extent, they do regulate the transcription process overall, however in my book they are called transcription factors. I think the term "regulatory protein" is reserved for proteins that have a more apparent regulatory process. just my two cents, I might be wrong though =P

 

[xtra333]

TFIID is required for licensing of the RNA polymerase though. that is why I thought choice C was right. just my opinion of course.