Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiota On Mucosal > B4 - Txn And Rna Processing > Flashcards

B4 - Txn And Rna Processing Flashcards

1
Q

If human genes are monocystronic, how is it organised in trypanosoma

A

Polycistronic (many genes same promoter)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What sort of tandem repeated gene families can you find and give example

A

Housekeeping proteins or developmentally regulated proteins

Hsp or tubulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Is mature mrna likeneuk capped and poly A and how (unlike pre mrna)

A

Yes but different process - via transsplicing get cap

By polyadenylation then add tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How can you get evidence polycisteonic exist eg through calmodulin tandem gene copies or vsg221

A

Block maturation into individual transcripts via cycloleucine or uv light

Visualise whole transcript

To make sure no promoter in interfenic space = reporter genes with cloned dna sequences of interfenic regions and won’t see gfp being expressed if not promoter/monocystronic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are cis-regulatory elements interacting with trans-elements in euk expression. And what does rna pol need to interact with promoter element

A

Cis is sites like promoter

Trans are proteins/tf interacting

Rna pol needs initiation complexes to recognise promoter and bind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What do the 3 rna pol transcribe usually

A

Rna pol 1 - RRNA
Pol II- pcg and U-snRna (uridine rich)
Pol III- trna

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why is rna pol 1 different in trypanosoma

A

Encodes also some pcg eg parp and vsg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What extra does pol III transcribe

A

U2 and 4 snrna

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How are the rna pol 1 promoters same for the transcripts eg vsg and parp

A

typical bipartite structure
Eg
Core promoter gc rich -45 to +20
Upstream gc rich region -180 to -107

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

are the trans-activators known in trypanosoma

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are promoters of normal pcg rna pol II different

A

They don’t have any!! Must have diff mech of transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does ctd (large subunit of rna pol 2) do in euk

A

Large subunit of rna pol II
Interacts with Tata binding proteins through heptapeptide repeats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is it diff in Tryp

A

phos

But not by tfIIH cak kinase domain because it doesn’t have one

Also no heptapeptide motif

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is trans splicing diff to cis in euk

A

Cis-splicing is removing introns through forming a lariat via the spliceosome

Trans splicing is the addition of a 39bp splice leader sequence to 5’ of each spliced individual transcript from premrna polycistron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is done on 3’ at same time

A

Poly adenylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is encoding these splice leader sequences , how many genes and where

A

Derived from SLrna 5’
Around 200 genes for SLrna somewhere not close to the mRNAs sometimes even on diff chromosomes to the transcripts
Transcribed through rna pol II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is it similar to cis

A

Because you’re rejoining 2 mrna transcripts to form mature rna

Polyadenylation via polyApolymerase

Also have u2,4 and 6 and sm proteins (but not 1 and 5 homologs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How many nucleotides are modified in the 5’ of slrna different to euk

A

4 (2 in euk)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which is the only known promoter of rna pol II

A

SLrna

20
Q

Which complex of polypeptides was found to bind tatabp on this promoter to induce txn

A

tSNAPc (t brucei)

21
Q

Is CTD important in this promoter

A

Yes (but not phos by tfIIH kinase cak

22
Q

What is methylated for translation on the cap nucleotides by metthltransferases

A

2’ o-ribose methylation

23
Q

RNA EDITING IN KT DNA OF MACXI CIRCLES

A

X

24
Q

What is meant by editing of the rna

A

After txn, (ptm) uridines are added or deleted from transcript to form mature mrna

These aren’t coded in the gene

25
Q

What gene in crithidia identified first for editing and what was added (maxicircle gene)

A

Cox subunit II (4 Us were added in 5’ end)

26
Q

What can U editing change

A

Stop codon, reading frame and start codons

27
Q

Give dramatic example

A

Cox subunit IiI
55% of nt are edited U residues in the last 2/3 of 3’

Inserted into polyA , codes a premature stop codon

28
Q

What do grna encdoed by minicircle a have on 5’ end of them

A

Anchor sequence complementary to the maxi circle dna 3’ of the editing site

29
Q

What do grna have on 3’ end

A

A poly U tail added post txn

30
Q

What adds and deletes Us at 3’ of cleaved fragment after cleaved by endonuclease

A

Tutase adds

ExoUase removes

31
Q

What rejoins them using atp

A

Rna ligase

32
Q

What is the 20s macromolecular complex called for rna editing

A

Editosome

33
Q

What does it associate with

A

Kinetoplast rna editing KRE proteins

Eg tutase, exoUase, ligase, helicase

34
Q

What frees the mrna strand from grna at end

A

Reh1 helicase

35
Q

What are the 2 subcomplexes found (3 proteins each) for addition or deletion

A

Addition complex -
KrepA1, KREL 2, tutase

Deletion
Krepa2, KREL 1, exoUase

36
Q

What are krepA proteins (6 of them)

A

Those with ob folds for rna-protein interaction

Unknown function

37
Q

What do the b barrel ob folds do

A

Ensure protein-rna interaction

38
Q

Which other multi protein complex found recently to interact with editosome

A

Mrb1 compelx

39
Q

The proteins contain which sorts of rna binding motifs

A

C2h2 zinc finger domain

Or rrm rna BD (rna recog motif)

40
Q

What 2 proteins important in the mrb1 core subcomplex (2 subcomplexes)

A

Gap1 and 2

41
Q

What do they do / the core subcomplex

A

Initiate the editing by grna through stabilising it

42
Q

What is the other subcomplex called

A

TbRgg2 complex

43
Q

What is this for and how does rgg2 do this

A

3’ to 5’ mrna editing progression

Rgg2 has high affinity rna recognition motif binding and binds rna

44
Q

How can you selectively block pol 2 and 3 to identify which is important at which point

A

A amanitin for pol 2

Tagetitoxin for pol 3

45
Q

Which sequence usually precedes the trans-splicing site in mrna processing (where SLrna is added)

A

Poly Y (pyrimidine chain)

Microbiota On Mucosal (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions