Biol 3090 exam 4, Chapter 9- Questions and Answers
Pre-mRNA processing in eukaryotes 5' capping, splicing, 3' end cleavage and polyadenylation
includes what 3 steps?
Shortly after___________initiates RNA polymerase II, 7-methylguanylate
transcription at the first nucleotide of the
exon of a gene, the 5' end of the nascent
RNA is capped with________ _.
What's R-looping? an early indication of eukaryotic pre-mRNA splicing (late 1970's).
In R-looping β-globin Pre-mRNA with one annealed back to its gene.
intron: pre-mRNA
is ?
In R-looping Mature β-globin mRNA remains double-stranded.
annealed back to its gene. Without intron in
the mRNA, intervening DNA?
5' splice site (GU)
In Splicing of Pre-mRNAs Important
- 3' splice site (AG)
regulatory sequences within the intron and
- Branch A
at exon/intron boundaries are?
- Pyrimidine rich region
What is traditionally called the donor site? 5' splice site (GU)
What is traditionally called the acceptor 3' splice site (AG)
site?
Branch A is______ nts upstream of the 3' 20-50
splice site.
Length of introns can vary from 40 nts 500,000
(minimum) to___ nts.
Mechanism of Pre-mRNA Splicing is? Two Trans-esterification reactions
, In Two Trans-esterification reactions one exchanged for another. -no energy required
phosphate bond is?
In Mechanism of Pre-mRNA Splicing the 2' 5' splice site (end of exon 1).
OH of branch A attacks? - lariat forms
Then In Mechanism of Pre-mRNA Splicing 3'splice site (beginning of exon 2).
the 3’ OH left at the end of first exon - exons are ligated together
attacks? which means? - lariat is freed.
Splicing intermediates are? In vitro splicing reactions using nuclear extracts.
AU-AC uses U11, U12, with special U4 and U6
What's AU-AC splicing? And how is it snurps splice AU---AC introns.
different from standard splicing?
1) U1 snRNP anneals to the 5’ splice site.
2) U2 snRNP anneals to the branch point A
What is a typical GU-AG splice? - notice the branch A residue is bulged out.
3) U4/U5/U6 snRNPs join as a trimeric complex.
U4 and U6 snRNAs are initially? annealed to each other.
U4 acts as a__________ for U6’s functional repressor, U2
interaction with____.
Spliceosome is complete with? all five snRNPs bound to the pre-mRNA
Once assembled, U6 RNA anneals to____to U2, branch A residue
help bulge out the ______ _ _______
U5 holds the________ in close proximity. 5' and 3' splice sites
the Branch A is pushed out from an RNA U2 snRNA and the intron's branch site.
helix formed between the ?
Ligated exons are? mature mRNA ready for export
heterogeneous nuclear Ribonucleoprotein Particles (hnRNPs) contain
hnRNP proteins: who are they?
heterogeneous nuclear RNA (aka, pre-mRNA)
hnRNP proteins: What do they do? Proteins coat pre-mRNAs to protect and stabilize RNA structures.
hnRNP proteins cDNAs are obtained by? expression cloning
RRM motif (a.k.a. RNP or RBD)
What are the motifs often found in RNA- 2) RGG motif (Arg-Gly-Gly)
binding proteins? 3) KH domain
4) SR motifs (Ser-Arg)
The_____________ is the most common RNA recognition motif (RRM or RNP or RBD), bind RNA
RNA-binding domain in hnRNP proteins. It
is approximately 80 - 90 amino acids long
and has four beta strands and two alpha
helices that work as a unit to_________ _.
The beta sheets form a positively charged
surface that interacts with negatively
charged RNA.
Pre-mRNA processing in eukaryotes 5' capping, splicing, 3' end cleavage and polyadenylation
includes what 3 steps?
Shortly after___________initiates RNA polymerase II, 7-methylguanylate
transcription at the first nucleotide of the
exon of a gene, the 5' end of the nascent
RNA is capped with________ _.
What's R-looping? an early indication of eukaryotic pre-mRNA splicing (late 1970's).
In R-looping β-globin Pre-mRNA with one annealed back to its gene.
intron: pre-mRNA
is ?
In R-looping Mature β-globin mRNA remains double-stranded.
annealed back to its gene. Without intron in
the mRNA, intervening DNA?
5' splice site (GU)
In Splicing of Pre-mRNAs Important
- 3' splice site (AG)
regulatory sequences within the intron and
- Branch A
at exon/intron boundaries are?
- Pyrimidine rich region
What is traditionally called the donor site? 5' splice site (GU)
What is traditionally called the acceptor 3' splice site (AG)
site?
Branch A is______ nts upstream of the 3' 20-50
splice site.
Length of introns can vary from 40 nts 500,000
(minimum) to___ nts.
Mechanism of Pre-mRNA Splicing is? Two Trans-esterification reactions
, In Two Trans-esterification reactions one exchanged for another. -no energy required
phosphate bond is?
In Mechanism of Pre-mRNA Splicing the 2' 5' splice site (end of exon 1).
OH of branch A attacks? - lariat forms
Then In Mechanism of Pre-mRNA Splicing 3'splice site (beginning of exon 2).
the 3’ OH left at the end of first exon - exons are ligated together
attacks? which means? - lariat is freed.
Splicing intermediates are? In vitro splicing reactions using nuclear extracts.
AU-AC uses U11, U12, with special U4 and U6
What's AU-AC splicing? And how is it snurps splice AU---AC introns.
different from standard splicing?
1) U1 snRNP anneals to the 5’ splice site.
2) U2 snRNP anneals to the branch point A
What is a typical GU-AG splice? - notice the branch A residue is bulged out.
3) U4/U5/U6 snRNPs join as a trimeric complex.
U4 and U6 snRNAs are initially? annealed to each other.
U4 acts as a__________ for U6’s functional repressor, U2
interaction with____.
Spliceosome is complete with? all five snRNPs bound to the pre-mRNA
Once assembled, U6 RNA anneals to____to U2, branch A residue
help bulge out the ______ _ _______
U5 holds the________ in close proximity. 5' and 3' splice sites
the Branch A is pushed out from an RNA U2 snRNA and the intron's branch site.
helix formed between the ?
Ligated exons are? mature mRNA ready for export
heterogeneous nuclear Ribonucleoprotein Particles (hnRNPs) contain
hnRNP proteins: who are they?
heterogeneous nuclear RNA (aka, pre-mRNA)
hnRNP proteins: What do they do? Proteins coat pre-mRNAs to protect and stabilize RNA structures.
hnRNP proteins cDNAs are obtained by? expression cloning
RRM motif (a.k.a. RNP or RBD)
What are the motifs often found in RNA- 2) RGG motif (Arg-Gly-Gly)
binding proteins? 3) KH domain
4) SR motifs (Ser-Arg)
The_____________ is the most common RNA recognition motif (RRM or RNP or RBD), bind RNA
RNA-binding domain in hnRNP proteins. It
is approximately 80 - 90 amino acids long
and has four beta strands and two alpha
helices that work as a unit to_________ _.
The beta sheets form a positively charged
surface that interacts with negatively
charged RNA.
