gene expression 2

Question 1

TRUE or FALSE - gene expression controlled in one level

Answer 1

FALSE- gene expression is controlled across multiple levels

Question 2

what is the composition of the gene (in terms of regions involved in gene expression)

Answer 2

gene (structural information for mRNA)
regulatory DNA sequences
- 5’ regulatory regions
- 3’ regulatory regions
promoter regions
enhancer regions

Question 3

what is the role of the 5’ regulatory region in control of gene expression

Answer 3

5’ region activates the gene allowing transcription
- promoters within this region allow docking of factors and transcription proteins

Question 4

types of RNA polymerases

Answer 4

RNA Polymerase 1 - for rRNA
RNA polymerase 2 - for mRNA +(ncRNA)
RNA polymerase 3 - tRNA, rRNA, non-coding RNA

Question 5

structure of RNA polymerase 2

Answer 5

12 subunits
requires other proteins (e.g TFIID)
CTD-C terminus tail

Question 6

what it a protein important with RNA polymerase 2 to recognise and initiate transcription

Answer 6

The TATA‑binding protein (TBP), which is part of the transcription factor TFIID.

Question 7

what is the TATA BOX

Answer 7

section on the gene that can start transcription of the gene (when core promoters allow binding factors to initiate)

Question 8

what do core promoters contain to initiate transcription

Answer 8

contain sequence modifications that allow binding factors -> initiate transcription

Question 9

what sequences are in the TATA box region

Answer 9

tarter sequence
that allows TFIID to bind

Question 10

what doe TFIID contain

Answer 10

TATA binding proteins (TBP)
TAFs (TBP- associated factors)
along with other factors

Question 11

what is the role of TBP during gene expression

Answer 11

saddle shaped protein allows association of further complexes to start transcription

Question 12

what proteins associate to form a horseshoe shaped structure in DNA region to allow gene expression

Answer 12

TFIID + TFIIA + TFBII

Question 13

how do transcription factors work to alter gene expression

Answer 13

activation from binding leads to conformational change allowing interaction of other transcription factors -> alter expression

Question 14

where are transcription factors found

Answer 14

present in enhancers - depends on the histones attached to their effect on the expression

Question 15

how do enhancer sequences work to alter gene expression

Answer 15

bind to transcription factors and interact with gene promotor regions, loosing and bending the DNA to increase the transcription