Question 1
Question
What is required for the protein surface to bind to the DNA surface?
Answer
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For the protein surface to be complimentary to the DNA surface
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For the protein surface to be positive (DNA backbone's are negative)
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For the protein surface to contain hydrophobic residues
Question 2
Question
In which groove can the order of base pairs be differentiated?
Answer
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Major groove
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Minor groove
Question 3
Question
The major groove is 15A wide
Question 4
Question
Which is smaller?
Answer
-
Major groove
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Minor groove
Question 5
Question
Proteins that bind in the major groove must be more specific than those that bind in the minor groove
Question 6
Question
Why is Arg such a useful residue?
Answer
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It has 2 H acceptors, so it can bind to guanine
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It has 2 H donors, so it can bind to guanine
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It has 2 H acceptors, so it can bind to cytosine
Question 7
Question
Which of the following can bind to both G & A
Question 8
Question
What is base stacking?
Answer
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Where hydrophobic bases stack to avoid water
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Where hydrophobic bases pull the DNA inwards to avoid water
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Where hydrophobic bases twist the DNA to avoid water
Question 9
Question
What is required for a protein to take advantage of base stacking?
Question 10
Question
10bp covers a distance of 34 A
Question 11
Answer
-
Long, repetitious and thin
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Long, non-repetitious and thick
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Short, repetitious and thin
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Long, repetitious and thick
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Short, non-repetitious and thin
Question 12
Question
DNA can bend 180 dgrees over how long a stretch?
Question 13
Question
What does Phage Lamda Repressor bind to?
Question 14
Question
What is being shown here?
Answer
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A half site
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A palindromic sequence
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A restriction site
Question 15
Question
How does Phage Lambda Repressor Work?
Answer
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Binds to bacterial DNA at the lambda cro gene
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Binds to phage DNA at the Lambda cro gene
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And blocking RNA polymerase binding
Question 16
Question
Phage Lambda Repressor binds to only one target sequence
Question 17
Question
The Phage Lambda repressor binds as a _
Question 18
Question
Each subunit attaches to the DNA using a _ and binds to the other subunits using a _
Answer
-
Alpha helix, alpha helix
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Alpha helix, nothing- it's a monomer
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Beta sheet, beta sheet
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Beta sheet, nothing- it's a monomer
Question 19
Question
Phage Lambda Repressor has multiple subunits because ...
Answer
-
It binds to a sequence long enough that the protein cannot be removed
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It binds to a sequence long enough that the sequence becomes unique int the DNA
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It binds more exactly - so it only has a single target sequence
Question 20
Question
Where does Phage Lambda Suppressor bind?
Question 21
Question
A non-specific interaction doesn't involve bonding with any particular base
Question 22
Question
List some specific interactions between Phage Lambda Repressor and DNA
Answer
-
Ser - G, and Gly - T,
-
Gly- T and Ser-G
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Gly- C- and Ser-T
Question 23
Question
The DNA sequence is all read from the same DNA strand
Question 24
Question
A helix-turn-helix motif is often used for reading DNA
Question 25
Question
Different alpha helices (of the helix-turn-helix) motif perform specific and non-specific interactions
Question 26
Question
Proteins don't have to land on the DNA in exactly the right spot, they only need to...
Question 27
Question
Methionine repressor...
Answer
-
prevents methionine production
-
prevents binding of methionine to tRNA
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prevents methionine being added to the amino acid chain
Question 28
Question
The Methionine Repressor binding site is...
Answer
-
Palindromic
-
Almost palindromic
-
8bp
-
16bp
Question 29
Question
The binding site of most helix-turn-helix proteins are 16-18bp long
Question 30
Question
How does the Methionine repressor bind to the DNA?
Question 31
Question
Two beta strands have the same diameter as an alpha helix
Question 32
Question
Specific interactions in the methionine repressor happen between Lysine, Threonine, A & G
Question 33
Question
Restrictions enzymes are part of the bacterial immunity... how?
Answer
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Recognises and destroys non-self DNA
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Cuts around viral DNA that has infected the genome
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Proteases break down the viral coat
Question 34
Question
Restriction enzymes and transferases come in pairs, with the restriction enzyme made first
Question 35
Question
How does EcoRI bind?
Answer
-
Phosphate backbone reactions in the minor groove
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Phosphate backbone reactions in the major groove
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Specific interactions in the minor groove
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Specific interactions in the major groover
Question 36
Question
EcoRI looks for 2 G-C on top of each other because they're more bendable
Question 37
Question
Where in the GAATTC sequence does EcoR1 cut?
Question 38
Question
Eco RI needs an Fe iron to bind
Question 39
Question
Where are the distortions of the DNA caused by EcoRI?
Answer
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In the centre of GAATTC
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G/AATT/C
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GA/AT/TC
Question 40
Question
Hydrophobic interactions in ECORI-DNA ineractions recognise what?
Answer
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AA atacking
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AT stacking
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TT stacking
Question 41
Question
ECORI uses water mediated interactions to assist DNA recognition
Question 42
Question
What is strange about the EcoRV restriction enzyme?
Question 43
Question
EcoRV forms a dimer
Question 44
Question
ECORV creates major distortions where?
Answer
-
In the middle
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At the ends
-
One residue in
Question 45
Question
ECORV binds to the backbone in the minor groove and wraps 'arms' around into the major groove
Question 46
Question
The recognition loops in the major groove cause...
Answer
-
H bonding between stacks
-
H bonding between A-G
-
H bonding between T-C
Question 47
Question
ECORV looks for ATAT bases
Question 48
Question
Where in the GCGC sequence does M.Hal methylate?
Answer
-
The first G
-
The first C
-
The second G
-
The last C
Question 49
Question
Methylation prevents the restriction enzyme from recognizing a sequence, so it cannot be cot
Question 50
Question
Describe the actions of methylases
Question 51
Question
Interactions 'pull out' one of the bases to gain chemical access
Question 52
Question
What is the donor for methylation?
Answer
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S-adenosyl-methionine
-
Methanol
-
Methide
Question 53
Question
How the methylation interaction studied?
Answer
-
The cystine had the 5th H replaced with an F
-
Trapping it in the active site
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The cystine had the 3rd H replaced with an F
Question 54
Question
Once in the active site, a thiol bond forms between the cystine and the cytosine so the methyl can be added
Question 55
Question
What is inserted to bind with the widowed G?
Question 56
Question
The inserted bases fill up the space left by the flipped out cytosine