usmleasr
Forum Guru
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Cloning a gene was followed by insertion and
ligation of the gene in expression vector. The protein
translated from this gene , then studied on a western blot,
and probed with 32P-DNA, yielding a positive result. These
findings eliminate which of the following substances as a
candidate for the likely gene product?
CREB
Protein kinase A
RNA polymerase
SP-1
Steroid receptor
explain me please
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| asmi
Forum Hero
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C.RNA POLYMERASE
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| usmleasr
Forum Guru
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explain me asmi please :oops:
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| asmi
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What i understood is that here in this case you have to remove introns which RNA polymerase cannot do.Genomic DNA contains introns .
I may be wrong in here , if so plz do explain me.
what is the answer usmleasr ?
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| usmleasr
Forum Guru
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ans is give as protein kinase A...i have no explanation :oops:
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| asmi
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:roll:
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| black_tulip
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I think PKA is the answer. It is talking about the interaction between protein and DNA. Only the proteins in nuclei or that can enter nuclei interact with DNA.
of these five proteins, only PKA works in the cytoplasm.
A. CREB
B. Protein kinase A
C. RNA polymerase
D. SP-1
E. Steroid receptor
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| asmi
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thanks..you have made it easy for us to understand the Q
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| usmleasr
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thanks..what is SP-1?
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| black_tulip
Forum Senior
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Sp1 is transcription factor, which extends 217 bp from the initiation of transcription. The putative binding sites for Sp1 includes nuclear factor Y (NF-Y), activator protein 2 ('AP-2'), CCAAT/enhancer-binding protein ('C/EBP') and E2F transcription factors.
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| Bela
Forum Guru
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Hehehehe! I just saw the same q on qbank. They were saying that in the experiment, the trial was done with a DNA probe, not an Ab; therefore, we should look for proteins that are DNA binding. Protein kinase A phosphorylates other proteins rather than act with DNA directly, therefore it would give a negative result with the DNA probe.
As for SP 1, simply put, it's a zinc finger transcription factor that controls gene expression. It's the housekeeping factor that allows important enzymes involved with transcription to function well.
buona notte a tutti 
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La vita e bella!
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| asmi
Forum Hero
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yep i too saw it in Q bank. today
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