1. Lecture 15
From Gene to Protein

2. ribose
deoxyribose H

3. Transcription: Translation
The synthesis of RNA using DNA as the template
Occurs in the nucleus
Translation
The synthesis of protein using mRNA as the template
Occurs in the cytoplasm
Requires ribosomes (free or attached to the rough ER)

4. Basic organization of a gene…..
Sequence-specific TFs
TATA
promoter
transcription unit

5. Transcription

6. Transcription - Initiation
Transcriptional Initiation: promoter of a gene
TATA box-binding factor (TBP) and other
general transcription factors
RNA polymerase
Sequence-specific transcription factors
Sequence-specific transcription factors promote formation of the PIC

8. Elongation
ribonucleotides are added to the growing chain by RNA polymerase II
uses DNA sequence as template
5’ to 3’ synthesis (anti-parallel to DNA)
opens up base pairs at a time
new RNA strand peels away from the DNA template as it is synthesized

9. Termination
termination: when polyadenylation signal is reached (AAUAAA)
1-35 nucleotides downstream – pre-mRNA is cut free from the RNA polymerase
RNA Polymerase continues on for hundreds of nucleotides….

10. Modification and Processing
5’ methylated cap
3’ poly A tail
splicing
Enzyme for 5’ cap: attached to RNA pol II

12. PAP – poly A polymerase

13. Introns – regulatory function
-alternative splicing

14. Translation - tRNA

15. Translation – the mRNA code

16. Translation: Initiation, Elongation and Termination

17. 2. Elongation

18. 3. Termination