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Flashcards in 4 RNA Synthesis Deck (25):
1

what does RNA pol 1 transcribe?

rRNA (nucleolar)

2

what does RNA pol 2 trasncribe?

pre-mRNA (heterogenous nuclear RNA)

3

what does RNA pol3 trans?

tRNA, 5s rRNA and other small RNA genes

4

the different RNA polymerases can be distinguished from one another by their sensitivity to what?

alpha-amanitin

5

in the transcription of rRNA, what promotes the binding of RNA pol1 to the regulatory region

Factor B and Factor S proteins

6

in the trans of 5S rRNA, what proteins allow RNA pol 3 to begin transcribing?

TF3A and TF3C bind the promoter which permits recruitment of TF3B and finally pol3

7

where are the promoters for RNA pol3 typically found?

within the gene

8

what are enhancers?

DNA sequences taht can up regulate transcription of neighboring genes
-located upstream, downstream, or within a gene

9

What is the purpose of a TATAA box?

this is the site where the polymerase binds and being transcribing.

10

name the order of proteins recruited to the TATAA box?
what is this group of proteins called?

1. TF2D
2. TF2B
3. TF2H
4. TF2E and RNA pol2 silmultaneously
-basal transcription factors (required for all genes)

11

what are the three major steps in mRNA processing?

1. capping
2. polyadenylation
3. splicing

12

what is the 5' cap at the end of eukaryotic mRNA composed of

7 methyl guanosine

13

after a gene is transcribed, what happens at the 3' end of mRNA?

a poly A tail is added

14

what sequence is found 10 to 30 nt up from the poly A tail?

AAUAAA

15

what is recognized by the cleavage and poly-adenylation specificity factor (CPSF)?

AAUAAA

16

are introns or exons found in mature mRNA

exons

17

what is the stepwise process of mRNA splicing?

1. cleavage at 5' exon intron junction and formation of a lariat
2. circulization of intron and nucleophilic attack
3. cleavage of 3' intron exon junction and ligation of neighboring exons

18

where does splicing take place?

spliceosomes, large ribonucleotide protein particles akin to ribosomes

19

what type of RNA do ribosomes contain?

small nuclear RNA (SNRNA's) U1, 2, 4, 5, 6

20

in general, what is a thalassemia?

abnormalitys of Hb proteins, mainly a deficiency in one of the subtypes

21

what is the correlate between splicing and thalassemia?

1/4 of all mutations in the globin gene are in regions that specify correct splicing

22

what is alternative splicing?

ways to splice a common transcript in a way that it produces multiple unique protein products. this is found in different cell types

23

what is rifampacin?

blocks initiation of bacterial RNA synthesis

24

what is actinomycin?

binds to double helical DNA and prevents it from being transcribed

25

recite the stepwise process of preparing cDNA from mRNA

1. anneal primers
2. use RT to make DNA copy
3. treat with alkali to degrade RNA
4. use DNA polymerase to synthesize complimentary DNA strand (will use the 3' hairpin loop as a template)
5. treat with S1 nuclease to cleave the loop