Question 1
Question
Of known structures (60-80% of genes) how many are multidomain proteins?
Question 2
Question
Different combinations of domains are advantageous because they allow the organism to specialise
Question 3
Question
How can we recognize domains?
Answer
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DNA sequencing
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Amino acid sequencing
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Structure
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Topology (fold)
Question 4
Question
Why are DNA/amino acid sequencing of little use when investigating relationships between proteins?
Answer
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As diversion occurs, sequence patterns are lost even as the fold remains the same
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They can detect short evolutionary relationships only
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The techniques for reading the sequences are unreliable
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Identical sequences can give different aa sequences/folds
Question 5
Question
When investigating using structure, how do we identify domains?
Question 6
Question
There is a limited number of folds in nature (10^3-4)
Question 7
Question
Structural similarity occurs from what kind of evolution?
Question 8
Question
Sequence is more highly conserved than protein structure
Question 9
Question
Define convergent evolution
Answer
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The independent evolution of similar features in different lineages
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The carrying of a feature from a common ancestor into two lines, which allows the reconvergence of the two lines into a single species again
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The dependent evolution of similar features in two species that interact/co-operate closely
Question 10
Question
How does the CATH system establish taxonomy?
Question 11
Question
Which of the following classifications would be in the Class portion of the CATH system
Answer
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Connectivity of fold
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Barrel
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Mostly alpha
Question 12
Question
Which of the following would be in the Architecture domain of the CATH system
Answer
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Mostly beta
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Both
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Two layer sandwitch
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Connectivity of fold
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Barrel
Question 13
Question
Put the following in order of their use in the CATH system
A- Class
B- Sequence Superfamily
C- Homologous Superfamily
D-Architecture
E- Topology
Answer
-
A-D-E-C-B
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B-A-C-E-D
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D-E-A-B-C
Question 14
Question
There are 3 classes, 32 architectures and 820 topologies in the CATH system
Question 15
Question
The SCOP classifications, in descending order, are Class-Superfamily-Family-Fold-Species
Question 16
Question
What is the specification after Superfamiy in the Pfam system?
Question 17
Question
All the systems agree in _% of cases
Question 18
Question
To be homologous, two proteins must have two of which of the following in common?
Answer
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Structural Similarity
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Sequence Similarity
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Functional Simiarity
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Species Similarity
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Genus Similarity
Question 19
Question
What is the following describing- a protein contained in two different species with a similar function due to divergent evolution
Question 20
Question
What is the following describing- changes to a sequence following gene duplication leads to a variant copy with an additional (usually similar) function in the same species
Question 21
Question
Give the two defining features of orthologues
Answer
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RMSD of >4
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High SI
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Low SI
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SI may be high or low
Question 22
Question
NAD is a co-enzyme found in all living cells that accepts and donates electrons
Question 23
Question
NAD is made of three nucleotides and a phosphate group
Question 24
Question
Which of the following binds NAD when present in a protein?
Answer
-
A Rossman Fold
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A Sherman Fold
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A Fieldman Fold
Question 25
Question
The Rossman Fold has it's 6 beta sheets arranged in what order?
Question 26
Question
In a Rossman fold, the crossover of the strands form the binding site
Question 27
Question
In lactate dehydrogenase, which terminal domain contains the Rossman fold?
Question 28
Question
What is the role of the C-terminal domain in dehydrogenases?
Question 29
Question
Lactate dehydrogenase catalyses lactate --> oxaloacetate
Question 30
Question
Malate dehydrogenase is structually identical to LADH, so why do they have different substrates?
Answer
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An SI of 17%
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They operate in cells where only one or the other is avalible
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Lactate and malate are structurally identical, but have different components
Question 31
Question
How can we tell two proteins are not homologues?
Answer
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They have a different function
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They have a different S.I
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They're found in different species
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They're structurally different
Question 32
Question
What is the following descrbing- the existence of a shared ancestry between two structures (in this case proteins)
Answer
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Homology
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Divergent evolution
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Convergent evolution
Question 33
Question
Alcohol dehydrogenase contains a Rossman fold
Question 34
Question
ADH and LDH have an RMSD of 2.2 & an S.I of 17%- what relationship do they share?
Question 35
Question
In the case of sequence diversity between proteins, surface residues change less than core/functional site residues
Question 36
Question
Where do residue insertions usually occur?
Question 37
Question
The functional diversity of a domain superfamily depends on the fold