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10 Cards in this Set
- Front
- Back
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The function of the 3 RNA polymerase, which genes do they transcribe
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pol1: 5.8s, 18s, 28s rRNA
pol2: protein coding genes, micro, small interfering, small nucleolar and small nuclear pol3: 5.0s rRNA, tRNA, small nuclear |
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What are the properties of the
1. Basal promoter. 2. proximal promoter. 3. Distal regulatory element (DRE) |
1. Basal: immediate upstream of TSS
2. Proximal: Also located immediate upstream of TSS. It is longer than basal promoter, as it's a few hundred bp. 3. DRE: located far upstream of the TSS, but can also be downstream of the gene, near the end. |
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Name the consensus sequences that will be used for splicing, and the location, and give the sequence for the one needs to know.
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Bre: -35
TATA: (-30) TATAA/TAA/T DPE: +30 INR: TSS, or +1 |
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What is the kozak sequence? make the particular important nucleotide in UPPER CASE.
What does it do? |
gccA/Gcc AUG G
In translation, the ribosomal unit starts translation on the first AUG codon it sees, if it falls in a favourable context. the Kozak motif overlaps with the AUG, and it contributes a major role in this favourable context. |
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Describes the prokaryote RNA pol complex. 2 major points
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DNA enters one end, and the CATALYTIC centre is a hollow core located in the centre of the enzyme. This is where the DNA template will unwound, and the template strand will be exposed.
2. The hollow region contains another region named RUDDER, which it seperates the DNA-RNA hybrid, keeping the number of basepairs to 9 nt. Underneath the rudder is a lid, and under that is where synthesized RNA exits. |
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Describe the C-terminal domain for the RNA pol II of the eukaryote. what are its two conformations?
What does the change from one to the other does? It's a heptamer of 7 amino acids, what's the key aminoacid residue and where is it located?? |
2 structures: spherical vs elongated (random coil). The change in conformation between spherical and elongated allows the RNA pol to leave the promoter and continue in elongation phase.
Residue serine at position 2 and 5 |
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What does the following general transcription factor do?
TFIID |
D: Makes up TBP and TAF.
TBP: horse saddle shape, binds to TATA motif, bends the DNA conformation to expose the DNA on either side of the TATA motif. Exposure facilitates the binding of other general transcription factors. -detrimental to nucleosome formation. TAF:Regulate the binding of TBP. Also recognize DPE and Inr motifs when TATA is not present. |
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What does TFIIB general transcription factor do?
Also TFII F and E? |
Recognize the BRE element in the promoter region that is upstream of the TSS, as this orientation ensures direction of the transcription is downstream only.
It also allows better positioning of the catalytic site of the holoenzyme onto the TSS. TFIIF: stabilize interaction between RNA pol II and TBP (TFIID) and TFIIB. Attracts TFIIE and regulate TFIIH. TFII E: attracts TFIIH. |
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What does TFIIH do? 2 uses.
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it's an actual enzyme with two activities.
A. helicase activity, unwinds DNA to start a transcription bubble. B. Phosphorylation of serine 2 and 5 on the C-terminal domain, changes from spherical to lock monster, which allows RNA pol to detach from promoter and go in elongation mode. |
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Where do all the General Transcription factors bind to?
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The basal promoter.
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