1. Initiation of transcription by Pol I
1) UBF binds UCE and core element
2) SL1 (selectivity factor 1) binds UBF (not DNA)
3) complex recruits Pol I
4) Pol I transcribes until
it hits a termination site

2. Initiation of Pol III transcription
1) TFIIIA binds C box
2) recruits TFIIIC
3) TFIIIB binds
4) Complex recruits Pol III
5) Pol III goes until
hits > 4 T's

3. Initiation of transcription by Pol III
1) TFIIIC binds box B
2) recruits TFIIIB
3) complex recruits Pol III
4) Pol III runs until
hits > 4 Ts

4. Initiation of transcription by Pol II
Basal transcription
1) TFIID binds TATAA box
2) TFIIA and TFIIB bind to
TFIID/DNA
3) Complex recruits Pol II
4) Still must recruit
TFIIE & TFIIH to
form initiation complex

5. Initiation of transcription by Pol II
Basal transcription
1) Once assemble initiation complex must start Pol II
2) TFIIH kinases CTD

6. Initiation of transcription by Pol II
Basal transcription
1) Once assemble initiation complex must start Pol II
2) TFIIH kinases CTD
negative charge
gets it started
3) Exchange initiation
for elongation factors

7. Initiation of transcription by Pol II
Basal transcription
1) Once assemble initiation complex must start Pol II
2) Kinase CTD
negative charge
gets it started
3) Exchange initiation
for elongation factors
4) Continues until
hits terminator

8. Initiation of transcription by Pol II
Basal transcription
1) Once assemble initiation complex must start Pol II
2) Kinase CTD
negative charge
gets it started
3) RNA pol II is paused
on many promoters!

9. Initiation of transcription by Pol II
Basal transcription
1) Once assemble initiation complex must start Pol II
2) Kinase CTD
negative charge
gets it started
3) RNA pol II is paused
on many promoters!
even of genes that
aren’t expressed!
(low [mRNA])

10. Initiation of transcription by Pol II
RNA pol II is paused on many promoters!
even of genes that aren’t expressed! (low [mRNA])
Early elongation is also
regulated!

11. Initiation of transcription by Pol II
RNA pol II is paused on many promoters!
even of genes that aren’t expressed! (low [mRNA])
Early elongation is also
regulated!
PTEFb kinases CTD to
stimulate processivity &
processing

12. Initiation of transcription by Pol II
RNA pol II is paused on many promoters!
even of genes that aren’t expressed! (low [mRNA])
Early elongation is also
regulated!
PTEFb kinases CTD to
stimulate processivity &
processing
Many genes have
short transcripts

13. Initiation of transcription by Pol II
RNA pol II is paused on many promoters!
even of genes that aren’t expressed! (low [mRNA])
Early elongation is also
regulated!
PTEFb kinases CTD to
stimulate processivity &
processing
Many genes have
short transcripts
Yet another new
level of control!

14. Transcription
Template strand determines next base
Positioned by H-bonds
until RNA polymerase
links 5’ P to 3’ OH
in front

15. Transcription
Template strand determines next base
Positioned by H-bonds
until RNA polymerase
links 5’ P to 3’ OH
in front
Energy comes
from hydrolysis
of 2 Pi

16. NTP enters E site & rotates into A site
Transcription
NTP enters E site & rotates into A site

17. NTP enters E site & rotates into A site
Transcription
NTP enters E site & rotates into A site
Specificity comes from trigger loop

18. Specificity comes from trigger loop
Transcription
Specificity comes from trigger loop
Mobile motif that swings into position & triggers catalysis

19. Specificity comes from trigger loop
Transcription
Specificity comes from trigger loop
Mobile motif that swings into position & triggers catalysis
Release of PPi
Triggers translocation

20. Transcription
Proofreading: when it makes a mistake it removes ~ 5 bases & tries again

21. Activated transcription by Pol II
Studied by mutating promoters for reporter genes

22. Activated transcription by Pol II
Studied by mutating promoters for reporter genes
Requires transcription factors and changes in chromatin

23. Activated transcription by Pol II
enhancers are sequences 5’ to TATAA
transcriptional activators bind them
have distinct DNA binding and activation domains

24. Activated transcription by Pol II
enhancers are sequences 5’ to TATAA
transcriptional activators bind them
have distinct DNA binding and activation domains
activation domain interacts with mediator
helps assemble initiation complex on TATAA

25. Activated transcription by Pol II
enhancers are sequences 5’ to TATAA
transcriptional activators bind them
have distinct DNA binding and activation domains
activation domain interacts with mediator
helps assemble initiation complex on TATAA
Recently identified “activating RNA”: bind enhancers & mediator

26. Activated transcription by Pol II
Other lncRNA “promote transcriptional poising” in yeast
lncRNA displaces
glucose-responsive
repressors & co-
repressors from genes
for galactose catabolism

27. Activated transcription by Pol II
Other lncRNA “promote transcriptional poising” in yeast
lncRNA displaces
glucose-responsive
repressors & co-
repressors from genes
for galactose catabolism
Speeds induction of
GAL genes