Gene Expression at the Molecular Level II: Non-coding RNAs

Which mechanism is NOT used by ncRNAs to bind to other molecules?
A) Complementary base-pairing between the ncRNA and DNA.
B) Complementary base-pairing between the ncRNA and RNA
C) A stem loop structure in the ncRNA binds to a specific DNA sequence.
D) A stem loop structure in the ncRNA binds to a specific protein structure.
E) Several stem loop structures form a shape that binds to a small molecule.Which mechanism is NOT used by ncRNAs to bind to other molecules?
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Which mechanism is NOT used by ncRNAs to bind to other molecules?
A) Complementary base-pairing between the ncRNA and DNA.
B) Complementary base-pairing between the ncRNA and RNA
C) A stem loop structure in the ncRNA binds to a specific DNA sequence.
D) A stem loop structure in the ncRNA binds to a specific protein structure.
E) Several stem loop structures form a shape that binds to a small molecule.Which mechanism is NOT used by ncRNAs to bind to other molecules?
A stem loop structure in the ncRNA binds to a specific DNA sequence.
The sequence of a short ncRNA is 5' AGCCCUAUGACGUU 3'. To what is this ncRNA likely to bind?
an mRNA that contains the sequence 3' GAUACUG 5'
What is required for ncRNAs to form stem-loop structures?
regions of complementary base-sequence
An ncRNA consists only of several stem loop structures. What is a likely function of this ncRNA?
binding to components of the ribosome and facilitating its assembly
The RNA sequences of some introns found in bacteria, mitochondria, chloroplasts, and some nuclear genes fold into 3-D structures that catalyze the removal of the introns. Therefore, the intron functions as a
ribozyme.
Which is an ncRNA that functions as a guide?
telomerase RNA component (TERC)
The RNA component of telomerase (TERC), has which function(s)?
guide
template
The protein component of telomerase has what enzymatic function?
It makes an DNA polymer using RNA as a template.
A scientist is studying the HOTAIR ncRNA in human cells growing in culture. She identifies a mutation in a cell line that she suspects may affect the function of HOTAIR. The mutation changes the sequence in region 2 from 5′-CUCCCUU-3′ to 5′-CUGGACG-3′ (see diagram). How will this mutation affect the function of HOTAIR?
The mutant HOTAIR will bind to different target genes than the normal HOTAIR, and it will inhibit their expression.
How does HOTAIR exert its function?
guide
scaffold
What is the function of the HOTAIR ncRNA?HOTAIR acts first as a scaffold, then as a guideFire and Mello studied the effect of RNAs made from plasmids on gene expression in the nematode C. elegans. The results from the two experimental treatments and the control are shown below. What can be concluded from these results?Double-stranded RNA degrades more mex-3 mRNA than antisense RNA.What is the first step in the production of a miRNA?transcription from a nuclear geneWhat is the first step in the production of a siRNA?infection with a virusHow does RISC recognize mRNAs for silencing?Complementary base pairing allows the miRNA or siRNA and the mRNA to interact.Craig Mellow investigated RNA interference by injecting antisense and double-stranded RNAs into C. elegans. If the antisense and double-stranded RNAs were very similar, but not identical, to C. elegans mex-3, what would be the results of their experiment?The C. elegans mex-3 RNA would be inhibited, but not degraded, so the embryos from worms injected with antisense and double-stranded RNA would be green.Certain drugs use RNA interference as a mechanism of action. What molecule would the active compounds of these drugs be composed of?nucleic acidIn targeting a protein to the ER lumen, the SRP RNA functionsas a scaffold to alter protein functionIn a strain of bacteria, a mutation changes the sequence of repeat 2 in the Crispr gene (see figure). How will this affect bacterial immunity?The bacteria will have adaptive immunity against second infection with bacteriophage A, C, and D, but not B.A mutation changes the sequence of the Cas1 gene so that Cas1 protein is no longer produced. How will this affect bacterial immunity?The bacteria will have no defense against the first infection with any bacteriophage. The bacteria not have adaptive immunity against any second infections.The miR-200 class of miRNAs have what effect on human health?They reduce tumor growth.What process in plants does an ncRNA called COOLAIR regulate?flowering only after being exposed to cold temperatures