Frage 1
Frage
DNA helicase unwinds DNA into ssDNA for what processes?
Antworten
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DNA repair
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DNA replication
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DNA recombination
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DNA destruction
Frage 2
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DNA helicase's process and translocate branched structures
Frage 3
Frage
Name (a) branched DNA structure(s)
Antworten
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Holliday junctions
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D loops
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Binary helix
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T loops
Frage 4
Frage
RNA helicases cannot destabilize RNA secondary structures
Frage 5
Frage
RNA helicases help in which of the following processes
A- Promote ribosome assembly
B- RNA translocation
C-RNA splicing
D- RNA editing and transport
E-RNA degredation
Antworten
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A, C & D
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B, C & E
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A only
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E only
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All of them
Frage 6
Frage
Some helicases can work on both RNA & DNA
Frage 7
Frage
Which of the following unwind RNA-DNA hybrids
Antworten
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RNA helicase, then DNA helicase
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DNA helicase, then RNA helicase
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RNA/DNA helicases
Frage 8
Frage
RNA/DNA helicases perform which of the following functions?
Frage 9
Frage
All helicases use energy from NTP hydrolysis to translocate along polynucleotides
Frage 10
Frage
Helicases are dependent on Fe2+
Frage 11
Frage
Helicases can take which of the following forms (commonly)
Antworten
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Hexamers
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Monomers
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Trimers
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Dimers
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Tetramers
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Pentamers
Frage 12
Frage
Helicases can have an oligomeric structure
Frage 13
Frage 14
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What is the difference between translocases and helicases?
Frage 15
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Give an example of a DNA/RNA unwinding helicase/translocase
Frage 16
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Name a helicase/translocase that effects protein motion on DNA
Frage 17
Frage
Name a necleoprotein complex remodelling helicase
Frage 18
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Name a DNA/RNA remodelling helicase
Frage 19
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Helicases are divided into seven superfamilies based on primary structure, and then 3 structural classes
Frage 20
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The two structural classes are monomers and dimers
Frage 21
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All helicases contain a Rec B fold
Frage 22
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EVERY helicase molecule contains which of the following?
Frage 23
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The _TP binding site and the nucleotide binding site on a helicase are allosterically linked
Frage 24
Frage
Type A helicases (like PCRA) travel in which direction?
Antworten
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3' > 5'
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5' > 3'
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Both ways
Frage 25
Frage
Rec D is a Type 2 helicase- in which direction does it travel?
Antworten
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5' > 3'
-
Both ways
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3' . 5'
Frage 26
Frage
Rec BCD is a bipolar helicase
Frage 27
Frage
In a bacterial Holliday Junction with a stalled replication fork, what is required to allow replication to continue?
Frage 28
Frage
If Holliday Junctions cannot be repaired, they lead to a cruciform structure
Frage 29
Frage
What is the slowest rate of movement of a helicase?
Antworten
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10 bp/sec
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8 bp/sec
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12 bp/sec
Frage 30
Frage
Rate of helicase movement is dramatically dependent on protein partners
Frage 31
Frage
The fastest known helicase moves around 4000 bp/sec
Frage 32
Frage
Define Helicase Processivity
Antworten
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How fast it moves along the DNA/RNA
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How far it can move before it falls off
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How far it moves per substrate hydrolysis
Frage 33
Frage
Helicases can move around 10-30,000 base pairs before falling off depending on the helicase (and it's protein partners)
Frage 34
Frage
Step size is a theoretical limit due to the entropy of NTP hydrolysis
Frage 35
Frage
Step size is the theoretical avg no of bp unwound per NTP hydrolysis cycle
Frage 36
Frage
The limit on step size = Energy required to melt the bp x step size
Frage 37
Frage
What is the experimental limit of step size?
Antworten
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0.3-3 bp
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0.5- 5bp
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0.7- 7 bp
Frage 38
Frage
What is this image showing?
Frage 39
Frage
Which of the following is believed to be the unwinding mechanism used by helicases?
Frage 40
Frage
PCRA is made of how many domains?
Antworten
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4 - 1A/B & 2A/B
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2 - 1A & 2A
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6 1A/B, 2A/B & 3A/B
Frage 41
Frage
PCRA activity is dependent on its protein partners
Frage 42
Frage
PCRA is an ATPase with...
Antworten
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A 3' > 5' polarity
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A 5' > 3' polarity
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A low rate of 30 bp/sec
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A high rate of 300 bp/sec
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A low processivity of 10 bp/sec
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A high processivity of 100 bp/sec
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A step size of 16 bp/ATP
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A step size of 6 bp/ATP
Frage 43
Frage
The conserved Helicase motifs of PCRA are in the accessory domains
Frage 44
Frage
Aromatic stacking occurs between the inserted aa and bp
Frage 45
Frage
Which of the following will bind to the DNA
Antworten
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Tryptophan
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Phenylalanine
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Tyrosine
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Histidine
Frage 46
Frage
The complex of PCRA-DNA remains the same during ATP binding and ATP hydrolysis
Frage 47
Frage
Duplex distortion in the PCRA substrate complex suggests a Passive unwinding system
Frage 48
Frage
Partner proteins are required by PCRA for which processes?
Antworten
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Loading
-
Unwinding
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Activation
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Catalytic modification
Frage 49
Frage
Hexameric helicases can be part of the replisome
Frage 50
Frage
Hexameric helicases have a toroidal strcture to confer high processivity
Frage 51
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ATP binds where on hexameric helicases?
Frage 52
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ssDNA is bound in the central channel to a 'spiral staircase' of bining loops
Frage 53
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ATP binding pocket changes _ around the ring
Frage 54
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ATP binding correlates with loop hight in the central channel