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