L18/19: Gene Regulation - mal operon Flashcards
1
Q
What are the 2 genes on the mal operon?
A
malP and malQ
2
Q
Is MalT a positive or negative regulatory protein?
A
- Positive
3
Q
What is the strength of the promoter for the malPQ operon?
A
- weak
- On its own, it initiates very little to almost no transcription
4
Q
MalPQ bings to the sigma/RNA Pol … (strongly or weakly)?
A
- weakly
5
Q
What is the signal molecule?
A
- Maltose
6
Q
When does the cell need to express the MalPQ enzymes?
A
- When there is maltose present in the cell
7
Q
What does the malPQ operon contain?
A
- Genes encoding proteins for the breakdown of maltose sugar
8
Q
What is MalT?
A
- A regulatory protein where the gene malT is found upstream from the mal operon
- The protein is involved in the regulation of the malPQ operon but not part of the operon.
9
Q
Is malT is constitutively expressed or is it environmentally-regulated?
A
It is constitutively expressed
10
Q
Can MalT’s natural conformation bind to the operator?
A
No
11
Q
What promotes transcription of malP and malQ?
A
- a form of MalT binds to the operator and helps RNA pol to bind and remain on the promoter
- MalT can help out when bound to maltose because maltose changes the shape of MalT and allow MalT-mal to bind to the operator.
12
Q
Where is the operator located?
A
- Upstream of the promoter.
