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