Errors in Organization and Control of Eukaryotic Genome lecture notes

1) Section 2.1 The DNA End replication problem (pg 9)

In Fig 7, under step (ii), the shortening of the ends of DNA after the removal of the last RNA primer should happen on the LAGGING STRAND instead of the leading strand. Please make the relevant changes.


2) Section II(A)1 Introns (pg 13)

As mentioned during the tutorial, in Fig 11, the pre-mRNA should NOT have the 5' cap and the poly A tail. Please cancel them out.

Chromatin remodeling

 

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Organisation of Pro and Eu genome tutorial Q5 essay [8 marks]

1. Are non-coding DNA sequences that are bound by transcription factors

2. involved in regulating gene expression

3. 3 types of control elements include: promoter, enhancers and silencers.   

4. Promoter serves as recognition site for transcription factors and RNA polymerase

5. [more details ..] -  TATA box within promoter (consisting of 5’-TATAAA-3’) is recognized and bound by general transcription factors to recruit RNA polymerase to the promoter region

6. [relate back to how transcription is influenced] -  binding only produces basal / low levels of transcription 

7. Enhancers are distal control elements bound by activators.

8. a looping mechanism brings the bound activator to interact with the RNA polymerase  and transcription factors at the TATA site

9. [relate back to how transcription is influenced] -  Interaction of activators with RNA polymerase and/or general transcription factors increases the transcription of a gene.                                           

10. Silencers are distal control elements bound by repressors, 

11. [relate back to how transcription is influenced] -  Interaction inhibit transcription / gene expression

11. [Extra: some examples by which repressors work] - 

·          binding of repressor to DNA control elements mask the binding site of activators; OR

·         Binding of repressor to silencer and a certain transcription factor prevents further assembly of general transcription factors

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(Diagram --> Ignore the coactivators)